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Raymond Hettinger72348842003-01-25 21:22:52 +00001 Python 2.3 Quick Reference
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002
Guido van Rossumc8180cc1994-08-05 15:57:31 +00003
Raymond Hettinger72348842003-01-25 21:22:52 +00004 25 Jan 2003 upgraded by Raymond Hettinger for Python 2.3
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00005 16 May 2001 upgraded by Richard Gruet and Simon Brunning for Python 2.0
6 2000/07/18 upgraded by Richard Gruet, rgruet@intraware.com for Python 1.5.2
7from V1.3 ref
81995/10/30, by Chris Hoffmann, choffman@vicorp.com
Guido van Rossumc8180cc1994-08-05 15:57:31 +00009
Andrew M. Kuchling13423f32001-08-06 17:43:49 +000010Based on:
11 Python Bestiary, Author: Ken Manheimer, ken.manheimer@nist.gov
12 Python manuals, Authors: Guido van Rossum and Fred Drake
13 What's new in Python 2.0, Authors: A.M. Kuchling and Moshe Zadka
14 python-mode.el, Author: Tim Peters, tim_one@email.msn.com
15
16 and the readers of comp.lang.python
17
18Python's nest: http://www.python.org Developement: http://
19python.sourceforge.net/ ActivePython : http://www.ActiveState.com/ASPN/
20Python/
21newsgroup: comp.lang.python Help desk: help@python.org
Raymond Hettinger72348842003-01-25 21:22:52 +000022Resources: http://starship.python.net/
23 http://www.vex.net/parnassus/
24 http://aspn.activestate.com/ASPN/Cookbook/Python
25FAQ: http://www.python.org/cgi-bin/faqw.py
Andrew M. Kuchling13423f32001-08-06 17:43:49 +000026Full documentation: http://www.python.org/doc/
Raymond Hettinger72348842003-01-25 21:22:52 +000027Excellent reference books:
28 Python Essential Reference by David Beazley (New Riders)
29 Python Pocket Reference by Mark Lutz (O'Reilly)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +000030
31
32Invocation Options
33
34python [-diOStuUvxX?] [-c command | script | - ] [args]
35
36 Invocation Options
37Option Effect
Raymond Hettinger72348842003-01-25 21:22:52 +000038-c cmd program passed in as string (terminates option list)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +000039-d Outputs parser debugging information (also PYTHONDEBUG=x)
Raymond Hettinger72348842003-01-25 21:22:52 +000040-E ignore environment variables (such as PYTHONPATH)
41-h print this help message and exit
Andrew M. Kuchling13423f32001-08-06 17:43:49 +000042-i Inspect interactively after running script (also PYTHONINSPECT=x) and
43 force prompts, even if stdin appears not to be a terminal
Raymond Hettinger72348842003-01-25 21:22:52 +000044-O optimize generated bytecode (a tad; also PYTHONOPTIMIZE=x)
45-OO remove doc-strings in addition to the -O optimizations
46-Q arg division options: -Qold (default), -Qwarn, -Qwarnall, -Qnew
Andrew M. Kuchling13423f32001-08-06 17:43:49 +000047-S Don't perform 'import site' on initialization
48-t Issue warnings about inconsistent tab usage (-tt: issue errors)
49-u Unbuffered binary stdout and stderr (also PYTHONUNBUFFERED=x).
Andrew M. Kuchling13423f32001-08-06 17:43:49 +000050-v Verbose (trace import statements) (also PYTHONVERBOSE=x)
Raymond Hettinger72348842003-01-25 21:22:52 +000051-W arg : warning control (arg is action:message:category:module:lineno)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +000052-x Skip first line of source, allowing use of non-unix Forms of #!cmd
Andrew M. Kuchling13423f32001-08-06 17:43:49 +000053-? Help!
54-c Specify the command to execute (see next section). This terminates the
55command option list (following options are passed as arguments to the command).
56 the name of a python file (.py) to execute read from stdin.
57script Anything afterward is passed as options to python script or command,
58 not interpreted as an option to interpreter itself.
59args passed to script or command (in sys.argv[1:])
60 If no script or command, Python enters interactive mode.
61
62 * Available IDEs in std distrib: IDLE (tkinter based, portable), Pythonwin
63 (Windows).
64
65
66
67Environment variables
68
69 Environment variables
70 Variable Effect
71PYTHONHOME Alternate prefix directory (or prefix;exec_prefix). The
72 default module search path uses prefix/lib
73 Augments the default search path for module files. The format
74 is the same as the shell's $PATH: one or more directory
75 pathnames separated by ':' or ';' without spaces around
76 (semi-)colons!
77PYTHONPATH On Windows first search for Registry key HKEY_LOCAL_MACHINE\
78 Software\Python\PythonCore\x.y\PythonPath (default value). You
79 may also define a key named after your application with a
80 default string value giving the root directory path of your
81 app.
82 If this is the name of a readable file, the Python commands in
83PYTHONSTARTUP that file are executed before the first prompt is displayed in
84 interactive mode (no default).
85PYTHONDEBUG If non-empty, same as -d option
86PYTHONINSPECT If non-empty, same as -i option
87PYTHONSUPPRESS If non-empty, same as -s option
88PYTHONUNBUFFERED If non-empty, same as -u option
89PYTHONVERBOSE If non-empty, same as -v option
90PYTHONCASEOK If non-empty, ignore case in file/module names (imports)
91
92
93
94
95Notable lexical entities
96
97Keywords
98
99 and del for is raise
100 assert elif from lambda return
101 break else global not try
102 class except if or while
Raymond Hettinger72348842003-01-25 21:22:52 +0000103 continue exec import pass yield
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000104 def finally in print
105
106 * (list of keywords in std module: keyword)
107 * Illegitimate Tokens (only valid in strings): @ $ ?
108 * A statement must all be on a single line. To break a statement over
109 multiple lines use "\", as with the C preprocessor.
110 Exception: can always break when inside any (), [], or {} pair, or in
111 triple-quoted strings.
112 * More than one statement can appear on a line if they are separated with
113 semicolons (";").
114 * Comments start with "#" and continue to end of line.
115
116Identifiers
117
118 (letter | "_") (letter | digit | "_")*
119
120 * Python identifiers keywords, attributes, etc. are case-sensitive.
121 * Special forms: _ident (not imported by 'from module import *'); __ident__
122 (system defined name);
123 __ident (class-private name mangling)
124
125Strings
126
127 "a string enclosed by double quotes"
128 'another string delimited by single quotes and with a " inside'
129 '''a string containing embedded newlines and quote (') marks, can be
130 delimited with triple quotes.'''
131 """ may also use 3- double quotes as delimiters """
132 u'a unicode string' U"Another unicode string"
133 r'a raw string where \ are kept (literalized): handy for regular
134 expressions and windows paths!'
135 R"another raw string" -- raw strings cannot end with a \
136 ur'a unicode raw string' UR"another raw unicode"
137
138 Use \ at end of line to continue a string on next line.
139 adjacent strings are concatened, e.g. 'Monty' ' Python' is the same as
140 'Monty Python'.
141 u'hello' + ' world' --> u'hello world' (coerced to unicode)
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000142
143 String Literal Escapes
144
145 \newline Ignored (escape newline)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000146 \\ Backslash (\) \e Escape (ESC) \v Vertical Tab (VT)
147 \' Single quote (') \f Formfeed (FF) \OOO char with octal value OOO
148 \" Double quote (") \n Linefeed (LF)
149 \a Bell (BEL) \r Carriage Return (CR) \xHH char with hex value HH
150 \b Backspace (BS) \t Horizontal Tab (TAB)
151 \uHHHH unicode char with hex value HHHH, can only be used in unicode string
152 \UHHHHHHHH unicode char with hex value HHHHHHHH, can only be used in unicode string
153 \AnyOtherChar is left as-is
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000154
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000155 * NUL byte (\000) is NOT an end-of-string marker; NULs may be embedded in
156 strings.
157 * Strings (and tuples) are immutable: they cannot be modified.
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000158
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000159Numbers
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000160
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000161 Decimal integer: 1234, 1234567890546378940L (or l)
Raymond Hettinger72348842003-01-25 21:22:52 +0000162 Octal integer: 0177, 0177777777777777777 (begin with a 0)
163 Hex integer: 0xFF, 0XFFFFffffFFFFFFFFFF (begin with 0x or 0X)
164 Long integer (unlimited precision): 1234567890123456
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000165 Float (double precision): 3.14e-10, .001, 10., 1E3
166 Complex: 1J, 2+3J, 4+5j (ends with J or j, + separates (float) real and
167 imaginary parts)
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000168
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000169Sequences
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000170
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000171 * String of length 0, 1, 2 (see above)
172 '', '1', "12", 'hello\n'
173 * Tuple of length 0, 1, 2, etc:
174 () (1,) (1,2) # parentheses are optional if len > 0
175 * List of length 0, 1, 2, etc:
176 [] [1] [1,2]
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000177
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000178Indexing is 0-based. Negative indices (usually) mean count backwards from end
179of sequence.
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000180
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000181Sequence slicing [starting-at-index : but-less-than-index]. Start defaults to
182'0'; End defaults to 'sequence-length'.
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000183
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000184a = (0,1,2,3,4,5,6,7)
185 a[3] ==> 3
186 a[-1] ==> 7
187 a[2:4] ==> (2, 3)
188 a[1:] ==> (1, 2, 3, 4, 5, 6, 7)
189 a[:3] ==> (0, 1, 2)
190 a[:] ==> (0,1,2,3,4,5,6,7) # makes a copy of the sequence.
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000191
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000192Dictionaries (Mappings)
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000193
Raymond Hettinger72348842003-01-25 21:22:52 +0000194 {} # Zero length empty dictionary
195 {1 : 'first'} # Dictionary with one (key, value) pair
196 {1 : 'first', 'next': 'second'}
197 dict([('one',1),('two',2)]) # Construct a dict from an item list
198 dict('one'=1, 'two'=2) # Construct a dict using keyword args
199 dict.fromkeys(['one', 'keys']) # Construct a dict from a sequence
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000200
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000201Operators and their evaluation order
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000202
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000203 Operators and their evaluation order
204Highest Operator Comment
205 (...) [...] {...} `...` Tuple, list & dict. creation; string
206 conv.
207 s[i] s[i:j] s.attr f(...) indexing & slicing; attributes, fct
208 calls
209 +x, -x, ~x Unary operators
210 x**y Power
Raymond Hettingere685f942003-01-26 03:29:15 +0000211 x*y x/y x%y x//y mult, division, modulo, floor division
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000212 x+y x-y addition, substraction
213 x<<y x>>y Bit shifting
214 x&y Bitwise and
215 x^y Bitwise exclusive or
216 x|y Bitwise or
217 x<y x<=y x>y x>=y x==y x!=y Comparison,
218 x<>y identity,
219 x is y x is not y membership
220 x in s x not in s
221 not x boolean negation
222 x and y boolean and
223 x or y boolean or
224Lowest lambda args: expr anonymous function
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000225
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000226Alternate names are defined in module operator (e.g. __add__ and add for +)
Raymond Hettinger72348842003-01-25 21:22:52 +0000227Most operators are overridable.
228
Raymond Hettinger5a772d32003-01-25 22:35:42 +0000229Many binary operators also support augmented assignment:
Raymond Hettinger72348842003-01-25 21:22:52 +0000230 x += 1 # Same as x = x + 1
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000231
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000232
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000233Basic Types and Their Operations
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000234
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000235Comparisons (defined between *any* types)
Guido van Rossumc8180cc1994-08-05 15:57:31 +0000236
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000237 Comparisons
238Comparison Meaning Notes
239< strictly less than (1)
240<= less than or equal to
241> strictly greater than
242>= greater than or equal to
243== equal to
244!= or <> not equal to
245is object identity (2)
246is not negated object identity (2)
247
248Notes :
249 Comparison behavior can be overridden for a given class by defining special
250method __cmp__.
Raymond Hettinger72348842003-01-25 21:22:52 +0000251 The above comparisions return True or False which are of type bool
Raymond Hettinger5a772d32003-01-25 22:35:42 +0000252(a subclass of int) and behave exactly as 1 or 0 except for their type and
Raymond Hettinger72348842003-01-25 21:22:52 +0000253that they print as True or False instead of 1 or 0.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000254 (1) X < Y < Z < W has expected meaning, unlike C
255 (2) Compare object identities (i.e. id(object)), not object values.
256
257Boolean values and operators
258
259 Boolean values and operators
260 Value or Operator Returns Notes
261None, numeric zeros, empty sequences and False
262mappings
263all other values True
264not x True if x is False, else
265 True
266x or y if x is False then y, else (1)
267 x
268x and y if x is False then x, else (1)
269 y
270
271Notes :
272 Truth testing behavior can be overridden for a given class by defining
273special method __nonzero__.
274 (1) Evaluate second arg only if necessary to determine outcome.
275
276None
277
278 None is used as default return value on functions. Built-in single object
279 with type NoneType.
280 Input that evaluates to None does not print when running Python
281 interactively.
282
283Numeric types
284
285Floats, integers and long integers.
286
287 Floats are implemented with C doubles.
288 Integers are implemented with C longs.
289 Long integers have unlimited size (only limit is system resources)
290
291Operators on all numeric types
292
293 Operators on all numeric types
294 Operation Result
295abs(x) the absolute value of x
296int(x) x converted to integer
297long(x) x converted to long integer
298float(x) x converted to floating point
299-x x negated
300+x x unchanged
301x + y the sum of x and y
302x - y difference of x and y
303x * y product of x and y
304x / y quotient of x and y
305x % y remainder of x / y
306divmod(x, y) the tuple (x/y, x%y)
307x ** y x to the power y (the same as pow(x, y))
308
309Bit operators on integers and long integers
310
311 Bit operators
312Operation >Result
313~x the bits of x inverted
314x ^ y bitwise exclusive or of x and y
315x & y bitwise and of x and y
316x | y bitwise or of x and y
317x << n x shifted left by n bits
318x >> n x shifted right by n bits
319
320Complex Numbers
321
322 * represented as a pair of machine-level double precision floating point
323 numbers.
324 * The real and imaginary value of a complex number z can be retrieved through
325 the attributes z.real and z.imag.
326
327Numeric exceptions
328
329TypeError
330 raised on application of arithmetic operation to non-number
331OverflowError
332 numeric bounds exceeded
333ZeroDivisionError
334 raised when zero second argument of div or modulo op
Raymond Hettingere685f942003-01-26 03:29:15 +0000335FloatingPointError
336 raised when a floating point operation fails
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000337
338Operations on all sequence types (lists, tuples, strings)
339
340 Operations on all sequence types
341Operation Result Notes
Raymond Hettingere685f942003-01-26 03:29:15 +0000342x in s True if an item of s is equal to x, else False
343x not in s False if an item of s is equal to x, else True
Raymond Hettinger72348842003-01-25 21:22:52 +0000344for x in s: loops over the sequence
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000345s + t the concatenation of s and t
346s * n, n*s n copies of s concatenated
347s[i] i'th item of s, origin 0 (1)
348s[i:j] slice of s from i (included) to j (excluded) (1), (2)
349len(s) length of s
350min(s) smallest item of s
351max(s) largest item of (s)
Raymond Hettinger72348842003-01-25 21:22:52 +0000352iter(s) returns an iterator over s. iterators define __iter__ and next()
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000353
354Notes :
355 (1) if i or j is negative, the index is relative to the end of the string,
356ie len(s)+ i or len(s)+j is
357 substituted. But note that -0 is still 0.
358 (2) The slice of s from i to j is defined as the sequence of items with
359index k such that i <= k < j.
360 If i or j is greater than len(s), use len(s). If i is omitted, use
361len(s). If i is greater than or
362 equal to j, the slice is empty.
363
364Operations on mutable (=modifiable) sequences (lists)
365
366 Operations on mutable sequences
367 Operation Result Notes
368s[i] =x item i of s is replaced by x
369s[i:j] = t slice of s from i to j is replaced by t
370del s[i:j] same as s[i:j] = []
371s.append(x) same as s[len(s) : len(s)] = [x]
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000372s.count(x) return number of i's for which s[i] == x
Raymond Hettingere685f942003-01-26 03:29:15 +0000373s.extend(x) same as s[len(s):len(s)]= x
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000374s.index(x) return smallest i such that s[i] == x (1)
375s.insert(i, x) same as s[i:i] = [x] if i >= 0
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000376s.pop([i]) same as x = s[i]; del s[i]; return x (4)
Raymond Hettinger72348842003-01-25 21:22:52 +0000377s.remove(x) same as del s[s.index(x)] (1)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000378s.reverse() reverse the items of s in place (3)
379s.sort([cmpFct]) sort the items of s in place (2), (3)
380
381Notes :
382 (1) raise a ValueError exception when x is not found in s (i.e. out of
383range).
384 (2) The sort() method takes an optional argument specifying a comparison
385fct of 2 arguments (list items) which should
386 return -1, 0, or 1 depending on whether the 1st argument is
387considered smaller than, equal to, or larger than the 2nd
388 argument. Note that this slows the sorting process down considerably.
389 (3) The sort() and reverse() methods modify the list in place for economy
390of space when sorting or reversing a large list.
391 They don't return the sorted or reversed list to remind you of this
392side effect.
Raymond Hettinger72348842003-01-25 21:22:52 +0000393 (4) [New 1.5.2] The optional argument i defaults to -1, so that by default the last
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000394item is removed and returned.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000395
396
397
398Operations on mappings (dictionaries)
399
400 Operations on mappings
401 Operation Result Notes
402len(d) the number of items in d
403d[k] the item of d with key k (1)
404d[k] = x set d[k] to x
405del d[k] remove d[k] from d (1)
406d.clear() remove all items from d
407d.copy() a shallow copy of d
Raymond Hettinger72348842003-01-25 21:22:52 +0000408d.get(k,defaultval) the item of d with key k (4)
Raymond Hettingere685f942003-01-26 03:29:15 +0000409d.has_key(k) True if d has key k, else False
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000410d.items() a copy of d's list of (key, item) pairs (2)
Raymond Hettinger72348842003-01-25 21:22:52 +0000411d.iteritems() an iterator over (key, value) pairs (7)
412d.iterkeys() an iterator over the keys of d (7)
413d.itervalues() an iterator over the values of d (7)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000414d.keys() a copy of d's list of keys (2)
415d1.update(d2) for k, v in d2.items(): d1[k] = v (3)
416d.values() a copy of d's list of values (2)
Raymond Hettinger72348842003-01-25 21:22:52 +0000417d.pop(k) remove d[k] and return its value
418d.popitem() remove and return an arbitrary (6)
419 (key, item) pair
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000420d.setdefault(k,defaultval) the item of d with key k (5)
421
422 Notes :
423 TypeError is raised if key is not acceptable
424 (1) KeyError is raised if key k is not in the map
425 (2) Keys and values are listed in random order
426 (3) d2 must be of the same type as d1
427 (4) Never raises an exception if k is not in the map, instead it returns
428 defaultVal.
429 defaultVal is optional, when not provided and k is not in the map,
430 None is returned.
431 (5) Never raises an exception if k is not in the map, instead it returns
432 defaultVal, and adds k to map with value defaultVal. defaultVal is
433 optional. When not provided and k is not in the map, None is returned and
434 added to map.
Raymond Hettinger72348842003-01-25 21:22:52 +0000435 (6) Raises a KeyError if the dictionary is emtpy.
436 (7) While iterating over a dictionary, the values may be updated but
437 the keys cannot be changed.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000438
439Operations on strings
440
441Note that these string methods largely (but not completely) supersede the
442functions available in the string module.
443
444
445 Operations on strings
446 Operation Result Notes
447s.capitalize() return a copy of s with only its first character
448 capitalized.
449s.center(width) return a copy of s centered in a string of length width (1)
450 .
451s.count(sub[ return the number of occurrences of substring sub in (2)
452,start[,end]]) string s.
Raymond Hettinger72348842003-01-25 21:22:52 +0000453s.decode(([ return a decoded version of s. (3)
454 encoding
455 [,errors]])
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000456s.encode([ return an encoded version of s. Default encoding is the
Raymond Hettinger72348842003-01-25 21:22:52 +0000457 encoding current default string encoding. (3)
458 [,errors]])
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000459s.endswith(suffix return true if s ends with the specified suffix, (2)
Raymond Hettinger72348842003-01-25 21:22:52 +0000460 [,start[,end]]) otherwise return False.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000461s.expandtabs([ return a copy of s where all tab characters are (4)
462tabsize]) expanded using spaces.
463s.find(sub[,start return the lowest index in s where substring sub is (2)
464[,end]]) found. Return -1 if sub is not found.
465s.index(sub[ like find(), but raise ValueError when the substring is (2)
466,start[,end]]) not found.
Raymond Hettinger72348842003-01-25 21:22:52 +0000467s.isalnum() return True if all characters in s are alphanumeric, (5)
468 False otherwise.
469s.isalpha() return True if all characters in s are alphabetic, (5)
470 False otherwise.
471s.isdigit() return True if all characters in s are digit (5)
472 characters, False otherwise.
473s.islower() return True if all characters in s are lowercase, False (6)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000474 otherwise.
Raymond Hettinger72348842003-01-25 21:22:52 +0000475s.isspace() return True if all characters in s are whitespace (5)
476 characters, False otherwise.
477s.istitle() return True if string s is a titlecased string, False (7)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000478 otherwise.
Raymond Hettinger72348842003-01-25 21:22:52 +0000479s.isupper() return True if all characters in s are uppercase, False (6)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000480 otherwise.
481s.join(seq) return a concatenation of the strings in the sequence
482 seq, seperated by 's's.
483s.ljust(width) return s left justified in a string of length width. (1),
484 (8)
485s.lower() return a copy of s converted to lowercase.
486s.lstrip() return a copy of s with leading whitespace removed.
487s.replace(old, return a copy of s with all occurrences of substring (9)
488new[, maxsplit]) old replaced by new.
489s.rfind(sub[ return the highest index in s where substring sub is (2)
490,start[,end]]) found. Return -1 if sub is not found.
491s.rindex(sub[ like rfind(), but raise ValueError when the substring (2)
492,start[,end]]) is not found.
493s.rjust(width) return s right justified in a string of length width. (1),
494 (8)
495s.rstrip() return a copy of s with trailing whitespace removed.
496s.split([sep[ return a list of the words in s, using sep as the (10)
497,maxsplit]]) delimiter string.
498s.splitlines([ return a list of the lines in s, breaking at line (11)
499keepends]) boundaries.
500s.startswith return true if s starts with the specified prefix,
501(prefix[,start[ otherwise return false. (2)
502,end]])
503s.strip() return a copy of s with leading and trailing whitespace
504 removed.
505s.swapcase() return a copy of s with uppercase characters converted
506 to lowercase and vice versa.
507 return a titlecased copy of s, i.e. words start with
508s.title() uppercase characters, all remaining cased characters
509 are lowercase.
510s.translate(table return a copy of s mapped through translation table (12)
511[,deletechars]) table.
512s.upper() return a copy of s converted to uppercase.
Raymond Hettinger5a772d32003-01-25 22:35:42 +0000513s.zfill(width) return a string padded with zeroes on the left side and
Raymond Hettinger72348842003-01-25 21:22:52 +0000514 sliding a minus sign left if necessary. never truncates.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000515
516Notes :
517 (1) Padding is done using spaces.
518 (2) If optional argument start is supplied, substring s[start:] is
519processed. If optional arguments start and end are supplied, substring s[start:
520end] is processed.
521 (3) Optional argument errors may be given to set a different error handling
522scheme. The default for errors is 'strict', meaning that encoding errors raise
523a ValueError. Other possible values are 'ignore' and 'replace'.
524 (4) If optional argument tabsize is not given, a tab size of 8 characters
525is assumed.
526 (5) Returns false if string s does not contain at least one character.
527 (6) Returns false if string s does not contain at least one cased
528character.
529 (7) A titlecased string is a string in which uppercase characters may only
530follow uncased characters and lowercase characters only cased ones.
531 (8) s is returned if width is less than len(s).
532 (9) If the optional argument maxsplit is given, only the first maxsplit
533occurrences are replaced.
534 (10) If sep is not specified or None, any whitespace string is a separator.
535If maxsplit is given, at most maxsplit splits are done.
536 (11) Line breaks are not included in the resulting list unless keepends is
537given and true.
538 (12) table must be a string of length 256. All characters occurring in the
539optional argument deletechars are removed prior to translation.
540
541String formatting with the % operator
542
543formatString % args--> evaluates to a string
544
545 * formatString uses C printf format codes : %, c, s, i, d, u, o, x, X, e, E,
546 f, g, G, r (details below).
547 * Width and precision may be a * to specify that an integer argument gives
548 the actual width or precision.
549 * The flag characters -, +, blank, # and 0 are understood. (details below)
550 * %s will convert any type argument to string (uses str() function)
551 * args may be a single arg or a tuple of args
552
553 '%s has %03d quote types.' % ('Python', 2) # => 'Python has 002 quote types.'
554
555 * Right-hand-side can also be a mapping:
556
557 a = '%(lang)s has %(c)03d quote types.' % {'c':2, 'lang':'Python}
558(vars() function very handy to use on right-hand-side.)
559
560 Format codes
561Conversion Meaning
562d Signed integer decimal.
563i Signed integer decimal.
564o Unsigned octal.
565u Unsigned decimal.
566x Unsigned hexidecimal (lowercase).
567X Unsigned hexidecimal (uppercase).
568e Floating point exponential format (lowercase).
569E Floating point exponential format (uppercase).
570f Floating point decimal format.
571F Floating point decimal format.
572g Same as "e" if exponent is greater than -4 or less than precision,
573 "f" otherwise.
574G Same as "E" if exponent is greater than -4 or less than precision,
575 "F" otherwise.
576c Single character (accepts integer or single character string).
577r String (converts any python object using repr()).
578s String (converts any python object using str()).
579% No argument is converted, results in a "%" character in the result.
580 (The complete specification is %%.)
581
582 Conversion flag characters
583Flag Meaning
584# The value conversion will use the ``alternate form''.
5850 The conversion will be zero padded.
586- The converted value is left adjusted (overrides "-").
587 (a space) A blank should be left before a positive number (or empty
588 string) produced by a signed conversion.
589+ A sign character ("+" or "-") will precede the conversion (overrides a
590 "space" flag).
591
592File Objects
593
594Created with built-in function open; may be created by other modules' functions
595as well.
596
597Operators on file objects
598
599 File operations
600 Operation Result
601f.close() Close file f.
602f.fileno() Get fileno (fd) for file f.
603f.flush() Flush file f's internal buffer.
Raymond Hettingere685f942003-01-26 03:29:15 +0000604f.isatty() True if file f is connected to a tty-like dev, else False.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000605f.read([size]) Read at most size bytes from file f and return as a string
606 object. If size omitted, read to EOF.
607f.readline() Read one entire line from file f.
608f.readlines() Read until EOF with readline() and return list of lines read.
609 Set file f's position, like "stdio's fseek()".
610f.seek(offset[, whence == 0 then use absolute indexing.
611whence=0]) whence == 1 then offset relative to current pos.
612 whence == 2 then offset relative to file end.
613f.tell() Return file f's current position (byte offset).
614f.write(str) Write string to file f.
615f.writelines(list Write list of strings to file f.
616)
617
618File Exceptions
619
620 EOFError
621 End-of-file hit when reading (may be raised many times, e.g. if f is a
622 tty).
623 IOError
Raymond Hettingere685f942003-01-26 03:29:15 +0000624 Other I/O-related I/O operation failure.
625 OSError
626 OS system call failed.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000627
628
629 Advanced Types
630
631 -See manuals for more details -
632 + Module objects
633 + Class objects
634 + Class instance objects
635 + Type objects (see module: types)
636 + File objects (see above)
637 + Slice objects
638 + XRange objects
639 + Callable types:
640 o User-defined (written in Python):
641 # User-defined Function objects
642 # User-defined Method objects
643 o Built-in (written in C):
644 # Built-in Function objects
645 # Built-in Method objects
646 + Internal Types:
647 o Code objects (byte-compile executable Python code: bytecode)
648 o Frame objects (execution frames)
649 o Traceback objects (stack trace of an exception)
650
651
652 Statements
653
654 pass -- Null statement
655 del name[,name]* -- Unbind name(s) from object. Object will be indirectly
656 (and automatically) deleted only if no longer referenced.
657 print [>> fileobject,] [s1 [, s2 ]* [,]
658 -- Writes to sys.stdout, or to fileobject if supplied.
659 Puts spaces between arguments. Puts newline at end
660 unless statement ends with comma.
661 Print is not required when running interactively,
662 simply typing an expression will print its value,
663 unless the value is None.
664 exec x [in globals [,locals]]
665 -- Executes x in namespaces provided. Defaults
666 to current namespaces. x can be a string, file
667 object or a function object.
668 callable(value,... [id=value], [*args], [**kw])
669 -- Call function callable with parameters. Parameters can
670 be passed by name or be omitted if function
671 defines default values. E.g. if callable is defined as
672 "def callable(p1=1, p2=2)"
673 "callable()" <=> "callable(1, 2)"
674 "callable(10)" <=> "callable(10, 2)"
675 "callable(p2=99)" <=> "callable(1, 99)"
676 *args is a tuple of positional arguments.
677 **kw is a dictionary of keyword arguments.
678
679 Assignment operators
680
681 Caption
682 Operator Result Notes
683 a = b Basic assignment - assign object b to label a (1)
684 a += b Roughly equivalent to a = a + b (2)
685 a -= b Roughly equivalent to a = a - b (2)
686 a *= b Roughly equivalent to a = a * b (2)
687 a /= b Roughly equivalent to a = a / b (2)
688 a %= b Roughly equivalent to a = a % b (2)
689 a **= b Roughly equivalent to a = a ** b (2)
690 a &= b Roughly equivalent to a = a & b (2)
691 a |= b Roughly equivalent to a = a | b (2)
692 a ^= b Roughly equivalent to a = a ^ b (2)
693 a >>= b Roughly equivalent to a = a >> b (2)
694 a <<= b Roughly equivalent to a = a << b (2)
695
696 Notes :
697 (1) Can unpack tuples, lists, and strings.
698 first, second = a[0:2]; [f, s] = range(2); c1,c2,c3='abc'
699 Tip: x,y = y,x swaps x and y.
700 (2) Not exactly equivalent - a is evaluated only once. Also, where
701 possible, operation performed in-place - a is modified rather than
702 replaced.
703
704 Control Flow
705
706 if condition: suite
707 [elif condition: suite]*
708 [else: suite] -- usual if/else_if/else statement
709 while condition: suite
710 [else: suite]
711 -- usual while statement. "else" suite is executed
712 after loop exits, unless the loop is exited with
713 "break"
714 for element in sequence: suite
715 [else: suite]
716 -- iterates over sequence, assigning each element to element.
717 Use built-in range function to iterate a number of times.
718 "else" suite executed at end unless loop exited
719 with "break"
720 break -- immediately exits "for" or "while" loop
721 continue -- immediately does next iteration of "for" or "while" loop
722 return [result] -- Exits from function (or method) and returns result (use a tuple to
723 return more than one value). If no result given, then returns None.
Raymond Hettingere685f942003-01-26 03:29:15 +0000724 yield result -- Freezes the execution frame of a generator and returns the result
725 to the iterator's .next() method. Upon the next call to next(),
726 resumes execution at the frozen point with all of the local variables
727 still intact.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000728
729 Exception Statements
730
731 assert expr[, message]
732 -- expr is evaluated. if false, raises exception AssertionError
733 with message. Inhibited if __debug__ is 0.
734 try: suite1
735 [except [exception [, value]: suite2]+
736 [else: suite3]
737 -- statements in suite1 are executed. If an exception occurs, look
738 in "except" clauses for matching <exception>. If matches or bare
739 "except" execute suite of that clause. If no exception happens
740 suite in "else" clause is executed after suite1.
741 If exception has a value, it is put in value.
742 exception can also be tuple of exceptions, e.g.
743 "except (KeyError, NameError), val: print val"
744 try: suite1
745 finally: suite2
746 -- statements in suite1 are executed. If no
747 exception, execute suite2 (even if suite1 is
748 exited with a "return", "break" or "continue"
749 statement). If exception did occur, executes
750 suite2 and then immediately reraises exception.
751 raise exception [,value [, traceback]]
752 -- raises exception with optional value
753 value. Arg traceback specifies a traceback object to
754 use when printing the exception's backtrace.
755 raise -- a raise statement without arguments re-raises
756 the last exception raised in the current function
757An exception is either a string (object) or a class instance.
758 Can create a new one simply by creating a new string:
759
760 my_exception = 'You did something wrong'
761 try:
762 if bad:
763 raise my_exception, bad
764 except my_exception, value:
765 print 'Oops', value
766
767Exception classes must be derived from the predefined class: Exception, e.g.:
768 class text_exception(Exception): pass
769 try:
770 if bad:
771 raise text_exception()
772 # This is a shorthand for the form
773 # "raise <class>, <instance>"
774 except Exception:
775 print 'Oops'
776 # This will be printed because
777 # text_exception is a subclass of Exception
778When an error message is printed for an unhandled exception which is a
779class, the class name is printed, then a colon and a space, and
780finally the instance converted to a string using the built-in function
781str().
782All built-in exception classes derives from StandardError, itself
783derived from Exception.
784
785Name Space Statements
786
787[1.51: On Mac & Windows, the case of module file names must now match the case
788as used
789 in the import statement]
790Packages (>1.5): a package is a name space which maps to a directory including
791 module(s) and the special initialization module '__init__.py'
792 (possibly empty). Packages/dirs can be nested. You address a
793 module's symbol via '[package.[package...]module.symbol's.
794import module1 [as name1] [, module2]*
795 -- imports modules. Members of module must be
796 referred to by qualifying with [package.]module name:
797 "import sys; print sys.argv:"
798 "import package1.subpackage.module; package1.subpackage.module.foo()"
799 module1 renamed as name1, if supplied.
800from module import name1 [as othername1] [, name2]*
801 -- imports names from module module in current namespace.
802 "from sys import argv; print argv"
803 "from package1 import module; module.foo()"
804 "from package1.module import foo; foo()"
805 name1 renamed as othername1, if supplied.
806from module import *
807 -- imports all names in module, except those starting with "_";
808 *to be used sparsely, beware of name clashes* :
809 "from sys import *; print argv"
810 "from package.module import *; print x'
811 NB: "from package import *" only imports the symbols defined
812 in the package's __init__.py file, not those in the
813 template modules!
814global name1 [, name2]*
815 -- names are from global scope (usually meaning from module)
816 rather than local (usually meaning only in function).
817 -- E.g. in fct without "global" statements, assuming
818 "a" is name that hasn't been used in fct or module
819 so far:
820 -Try to read from "a" -> NameError
821 -Try to write to "a" -> creates "a" local to fcn
822 -If "a" not defined in fct, but is in module, then
823 -Try to read from "a", gets value from module
824 -Try to write to "a", creates "a" local to fct
825 But note "a[0]=3" starts with search for "a",
826 will use to global "a" if no local "a".
827
828Function Definition
829
830def func_id ([param_list]): suite
831 -- Creates a function object & binds it to name func_id.
832
833 param_list ::= [id [, id]*]
834 id ::= value | id = value | *id | **id
835 [Args are passed by value.Thus only args representing a mutable object
836 can be modified (are inout parameters). Use a tuple to return more than
837 one value]
838
839Example:
840 def test (p1, p2 = 1+1, *rest, **keywords):
841 -- Parameters with "=" have default value (v is
842 evaluated when function defined).
843 If list has "*id" then id is assigned a tuple of
844 all remaining args passed to function (like C vararg)
845 If list has "**id" then id is assigned a dictionary of
846 all extra arguments passed as keywords.
847
848Class Definition
849
850class <class_id> [(<super_class1> [,<super_class2>]*)]: <suite>
851 -- Creates a class object and assigns it name <class_id>
852 <suite> may contain local "defs" of class methods and
853 assignments to class attributes.
854Example:
855 class my_class (class1, class_list[3]): ...
856 Creates a class object inheriting from both "class1" and whatever
857 class object "class_list[3]" evaluates to. Assigns new
858 class object to name "my_class".
859 - First arg to class methods is always instance object, called 'self'
860 by convention.
861 - Special method __init__() is called when instance is created.
862 - Special method __del__() called when no more reference to object.
863 - Create instance by "calling" class object, possibly with arg
864 (thus instance=apply(aClassObject, args...) creates an instance!)
865 - In current implementation, can't subclass off built-in
866 classes. But can "wrap" them, see UserDict & UserList modules,
867 and see __getattr__() below.
868Example:
869 class c (c_parent):
870 def __init__(self, name): self.name = name
871 def print_name(self): print "I'm", self.name
872 def call_parent(self): c_parent.print_name(self)
873 instance = c('tom')
874 print instance.name
875 'tom'
876 instance.print_name()
877 "I'm tom"
878 Call parent's super class by accessing parent's method
879 directly and passing "self" explicitly (see "call_parent"
880 in example above).
881 Many other special methods available for implementing
882 arithmetic operators, sequence, mapping indexing, etc.
883
884Documentation Strings
885
886Modules, classes and functions may be documented by placing a string literal by
887itself as the first statement in the suite. The documentation can be retrieved
888by getting the '__doc__' attribute from the module, class or function.
889Example:
890 class C:
891 "A description of C"
892 def __init__(self):
893 "A description of the constructor"
894 # etc.
895Then c.__doc__ == "A description of C".
896Then c.__init__.__doc__ == "A description of the constructor".
897
898Others
899
900lambda [param_list]: returnedExpr
901 -- Creates an anonymous function. returnedExpr must be
902 an expression, not a statement (e.g., not "if xx:...",
903 "print xxx", etc.) and thus can't contain newlines.
904 Used mostly for filter(), map(), reduce() functions, and GUI callbacks..
905List comprehensions
906result = [expression for item1 in sequence1 [if condition1]
907 [for item2 in sequence2 ... for itemN in sequenceN]
908 ]
909is equivalent to:
910result = []
911for item1 in sequence1:
912 for item2 in sequence2:
913 ...
914 for itemN in sequenceN:
915 if (condition1) and furthur conditions:
916 result.append(expression)
917
918
919
920Built-In Functions
921
922 Built-In Functions
923 Function Result
924__import__(name[, Imports module within the given context (see lib ref for
925globals[, locals[, more details)
926fromlist]]])
927abs(x) Return the absolute value of number x.
928apply(f, args[, Calls func/method f with arguments args and optional
929keywords]) keywords.
Raymond Hettingere685f942003-01-26 03:29:15 +0000930bool(x) Returns True when the argument x is true and False otherwise.
931buffer(obj) Creates a buffer reference to an object.
932callable(x) Returns True if x callable, else False.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000933chr(i) Returns one-character string whose ASCII code isinteger i
Raymond Hettingere685f942003-01-26 03:29:15 +0000934classmethod(f) Converts a function f, into a method with the class as the
935 first argument. Useful for creating alternative constructors.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000936cmp(x,y) Returns negative, 0, positive if x <, ==, > to y
937coerce(x,y) Returns a tuple of the two numeric arguments converted to a
938 common type.
939 Compiles string into a code object.filename is used in
940 error message, can be any string. It isusually the file
941compile(string, from which the code was read, or eg. '<string>'if not read
942filename, kind) from file.kind can be 'eval' if string is a single stmt, or
943 'single' which prints the output of expression statements
944 thatevaluate to something else than None, or be 'exec'.
945complex(real[, Builds a complex object (can also be done using J or j
946image]) suffix,e.g. 1+3J)
947delattr(obj, name) deletes attribute named name of object obj <=> del obj.name
948 If no args, returns the list of names in current
Raymond Hettingere685f942003-01-26 03:29:15 +0000949dict([items]) Create a new dictionary from the specified item list.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000950dir([object]) localsymbol table. With a module, class or class
951 instanceobject as arg, returns list of names in its attr.
952 dict.
953divmod(a,b) Returns tuple of (a/b, a%b)
Raymond Hettingere685f942003-01-26 03:29:15 +0000954enumerate(seq) Return a iterator giving: (0, seq[0]), (1, seq[1]), ...
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000955eval(s[, globals[, Eval string s in (optional) globals, locals contexts.s must
956locals]]) have no NUL's or newlines. s can also be acode object.
957 Example: x = 1; incr_x = eval('x + 1')
958execfile(file[, Executes a file without creating a new module, unlike
959globals[, locals]]) import.
Raymond Hettingere685f942003-01-26 03:29:15 +0000960file() Synonym for open().
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000961filter(function, Constructs a list from those elements of sequence for which
962sequence) function returns true. function takes one parameter.
963float(x) Converts a number or a string to floating point.
964getattr(object, [<default> arg added in 1.5.2]Gets attribute called name
965name[, default])) from object,e.g. getattr(x, 'f') <=> x.f). If not found,
966 raisesAttributeError or returns default if specified.
967globals() Returns a dictionary containing current global variables.
968hasattr(object, Returns true if object has attr called name.
969name)
970hash(object) Returns the hash value of the object (if it has one)
Raymond Hettingere685f942003-01-26 03:29:15 +0000971help(f) Display documentation on object f.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000972hex(x) Converts a number x to a hexadecimal string.
973id(object) Returns a unique 'identity' integer for an object.
974input([prompt]) Prints prompt if given. Reads input and evaluates it.
975 Converts a number or a string to a plain integer. Optional
976int(x[, base]) base paramenter specifies base from which to convert string
977 values.
978intern(aString) Enters aString in the table of "interned strings"
979 andreturns the string. Interned strings are 'immortals'.
980isinstance(obj, returns true if obj is an instance of class. Ifissubclass
981class) (A,B) then isinstance(x,A) => isinstance(x,B)
982issubclass(class1, returns true if class1 is derived from class2
983class2)
984 Returns the length (the number of items) of an object
Raymond Hettingere685f942003-01-26 03:29:15 +0000985iter(collection) Returns an iterator over the collection.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +0000986len(obj) (sequence, dictionary, or instance of class implementing
987 __len__).
988list(sequence) Converts sequence into a list. If already a list,returns a
989 copy of it.
990locals() Returns a dictionary containing current local variables.
991 Converts a number or a string to a long integer. Optional
992long(x[, base]) base paramenter specifies base from which to convert string
993 values.
994 Applies function to every item of list and returns a listof
995map(function, list, the results. If additional arguments are passed,function
996...) must take that many arguments and it is givento function on
997 each call.
998max(seq) Returns the largest item of the non-empty sequence seq.
999min(seq) Returns the smallest item of a non-empty sequence seq.
1000oct(x) Converts a number to an octal string.
1001open(filename [, Returns a new file object. First two args are same asthose
1002mode='r', [bufsize= for C's "stdio open" function. bufsize is 0for unbuffered,
1003implementation 1 for line-buffered, negative forsys-default, all else, of
1004dependent]]) (about) given size.
1005ord(c) Returns integer ASCII value of c (a string of len 1). Works
1006 with Unicode char.
Raymond Hettingere685f942003-01-26 03:29:15 +00001007object() Create a base type. Used as a superclass for new-style objects.
1008open(name Open a file.
1009 [, mode
1010 [, buffering]])
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001011pow(x, y [, z]) Returns x to power y [modulo z]. See also ** operator.
Raymond Hettingere685f942003-01-26 03:29:15 +00001012property() Created a property with access controlled by functions.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001013range(start [,end Returns list of ints from >= start and < end.With 1 arg,
1014[, step]]) list from 0..arg-1With 2 args, list from start..end-1With 3
1015 args, list from start up to end by step
1016raw_input([prompt]) Prints prompt if given, then reads string from stdinput (no
1017 trailing \n). See also input().
1018reduce(f, list [, Applies the binary function f to the items oflist so as to
1019init]) reduce the list to a single value.If init given, it is
1020 "prepended" to list.
1021 Re-parses and re-initializes an already imported module.
1022 Useful in interactive mode, if you want to reload amodule
1023reload(module) after fixing it. If module was syntacticallycorrect but had
1024 an error in initialization, mustimport it one more time
1025 before calling reload().
1026 Returns a string containing a printable and if possible
1027repr(object) evaluable representation of an object. <=> `object`
1028 (usingbackquotes). Class redefinissable (__repr__). See
1029 also str()
1030round(x, n=0) Returns the floating point value x rounded to n digitsafter
1031 the decimal point.
1032setattr(object, This is the counterpart of getattr().setattr(o, 'foobar',
1033name, value) 3) <=> o.foobar = 3Creates attribute if it doesn't exist!
1034slice([start,] stop Returns a slice object representing a range, with R/
1035[, step]) Oattributes: start, stop, step.
1036 Returns a string containing a nicely
Raymond Hettingere685f942003-01-26 03:29:15 +00001037staticmethod() Convert a function to method with no self or class
1038 argument. Useful for methods associated with a class that
1039 do not need access to an object's internal state.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001040str(object) printablerepresentation of an object. Class overridable
1041 (__str__).See also repr().
Raymond Hettingere685f942003-01-26 03:29:15 +00001042super(type) Create an unbound super object. Used to call cooperative
1043 superclass methods.
Raymond Hettingerca60cac2003-07-12 23:55:57 +00001044sum(sequence, Add the values in the sequence and return the sum.
1045 [start])
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001046tuple(sequence) Creates a tuple with same elements as sequence. If already
1047 a tuple, return itself (not a copy).
1048 Returns a type object [see module types] representing
1049 thetype of obj. Example: import typesif type(x) ==
1050type(obj) types.StringType: print 'It is a string'NB: it is
1051 recommanded to use the following form:if isinstance(x,
1052 types.StringType): etc...
1053unichr(code) code.
1054unicode(string[, Creates a Unicode string from a 8-bit string, using
1055encoding[, error thegiven encoding name and error treatment ('strict',
1056]]]) 'ignore',or 'replace'}.
1057 Without arguments, returns a dictionary correspondingto the
1058 current local symbol table. With a module,class or class
1059vars([object]) instance object as argumentreturns a dictionary
1060 corresponding to the object'ssymbol table. Useful with "%"
1061 formatting operator.
1062xrange(start [, end Like range(), but doesn't actually store entire listall at
1063[, step]]) once. Good to use in "for" loops when there is abig range
1064 and little memory.
1065zip(seq1[, seq2, Returns a list of tuples where each tuple contains the nth
1066...]) element of each of the argument sequences.
1067
1068
1069
1070
1071Built-In Exceptions
1072
1073Exception>
1074 Root class for all exceptions
1075 SystemExit
1076 On 'sys.exit()'
Raymond Hettingere685f942003-01-26 03:29:15 +00001077 StopIteration
1078 Signal the end from iterator.next()
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001079 StandardError
1080 Base class for all built-in exceptions; derived from Exception
1081 root class.
1082 ArithmeticError
1083 Base class for OverflowError, ZeroDivisionError,
1084 FloatingPointError
1085 FloatingPointError
1086 When a floating point operation fails.
1087 OverflowError
1088 On excessively large arithmetic operation
1089 ZeroDivisionError
1090 On division or modulo operation with 0 as 2nd arg
1091 AssertionError
1092 When an assert statement fails.
1093 AttributeError
1094 On attribute reference or assignment failure
1095 EnvironmentError [new in 1.5.2]
1096 On error outside Python; error arg tuple is (errno, errMsg...)
1097 IOError [changed in 1.5.2]
1098 I/O-related operation failure
1099 OSError [new in 1.5.2]
1100 used by the os module's os.error exception.
1101 EOFError
1102 Immediate end-of-file hit by input() or raw_input()
1103 ImportError
1104 On failure of `import' to find module or name
1105 KeyboardInterrupt
1106 On user entry of the interrupt key (often `Control-C')
1107 LookupError
1108 base class for IndexError, KeyError
1109 IndexError
1110 On out-of-range sequence subscript
1111 KeyError
1112 On reference to a non-existent mapping (dict) key
1113 MemoryError
1114 On recoverable memory exhaustion
1115 NameError
1116 On failure to find a local or global (unqualified) name
1117 RuntimeError
1118 Obsolete catch-all; define a suitable error instead
1119 NotImplementedError [new in 1.5.2]
1120 On method not implemented
1121 SyntaxError
1122 On parser encountering a syntax error
1123 IndentationError
1124 On parser encountering an indentation syntax error
1125 TabError
1126 On parser encountering an indentation syntax error
1127 SystemError
1128 On non-fatal interpreter error - bug - report it
1129 TypeError
1130 On passing inappropriate type to built-in op or func
1131 ValueError
1132 On arg error not covered by TypeError or more precise
Raymond Hettingere685f942003-01-26 03:29:15 +00001133 Warning
1134 UserWarning
1135 DeprecationWarning
1136 PendingDeprecationWarning
1137 SyntaxWarning
1138 OverflowWarning
1139 RuntimeWarning
1140 FutureWarning
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001141
1142
1143
1144Standard methods & operators redefinition in classes
1145
1146Standard methods & operators map to special '__methods__' and thus may be
1147 redefined (mostly in in user-defined classes), e.g.:
1148 class x:
1149 def __init__(self, v): self.value = v
1150 def __add__(self, r): return self.value + r
1151 a = x(3) # sort of like calling x.__init__(a, 3)
1152 a + 4 # is equivalent to a.__add__(4)
1153
1154Special methods for any class
1155
1156(s: self, o: other)
1157 __init__(s, args) instance initialization (on construction)
1158 __del__(s) called on object demise (refcount becomes 0)
1159 __repr__(s) repr() and `...` conversions
1160 __str__(s) str() and 'print' statement
1161 __cmp__(s, o) Compares s to o and returns <0, 0, or >0.
1162 Implements >, <, == etc...
1163 __hash__(s) Compute a 32 bit hash code; hash() and dictionary ops
Raymond Hettingere685f942003-01-26 03:29:15 +00001164 __nonzero__(s) Returns False or True for truth value testing
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001165 __getattr__(s, name) called when attr lookup doesn't find <name>
1166 __setattr__(s, name, val) called when setting an attr
1167 (inside, don't use "self.name = value"
1168 use "self.__dict__[name] = val")
1169 __delattr__(s, name) called to delete attr <name>
1170 __call__(self, *args) called when an instance is called as function.
1171
1172Operators
1173
1174 See list in the operator module. Operator function names are provided with
1175 2 variants, with or without
1176 ading & trailing '__' (eg. __add__ or add).
1177
1178 Numeric operations special methods
1179 (s: self, o: other)
1180
1181 s+o = __add__(s,o) s-o = __sub__(s,o)
1182 s*o = __mul__(s,o) s/o = __div__(s,o)
1183 s%o = __mod__(s,o) divmod(s,o) = __divmod__(s,o)
1184 s**o = __pow__(s,o)
1185 s&o = __and__(s,o)
1186 s^o = __xor__(s,o) s|o = __or__(s,o)
1187 s<<o = __lshift__(s,o) s>>o = __rshift__(s,o)
1188 nonzero(s) = __nonzero__(s) (used in boolean testing)
1189 -s = __neg__(s) +s = __pos__(s)
1190 abs(s) = __abs__(s) ~s = __invert__(s) (bitwise)
1191 s+=o = __iadd__(s,o) s-=o = __isub__(s,o)
1192 s*=o = __imul__(s,o) s/=o = __idiv__(s,o)
1193 s%=o = __imod__(s,o)
1194 s**=o = __ipow__(s,o)
1195 s&=o = __iand__(s,o)
1196 s^=o = __ixor__(s,o) s|=o = __ior__(s,o)
1197 s<<=o = __ilshift__(s,o) s>>=o = __irshift__(s,o)
1198 Conversions
1199 int(s) = __int__(s) long(s) = __long__(s)
1200 float(s) = __float__(s) complex(s) = __complex__(s)
1201 oct(s) = __oct__(s) hex(s) = __hex__(s)
1202 coerce(s,o) = __coerce__(s,o)
1203 Right-hand-side equivalents for all binary operators exist;
1204 are called when class instance is on r-h-s of operator:
1205 a + 3 calls __add__(a, 3)
1206 3 + a calls __radd__(a, 3)
1207
1208 All seqs and maps, general operations plus:
1209 (s: self, i: index or key)
1210
1211 len(s) = __len__(s) length of object, >= 0. Length 0 == false
1212 s[i] = __getitem__(s,i) Element at index/key i, origin 0
1213
1214 Sequences, general methods, plus:
1215 s[i]=v = __setitem__(s,i,v)
1216 del s[i] = __delitem__(s,i)
1217 s[i:j] = __getslice__(s,i,j)
1218 s[i:j]=seq = __setslice__(s,i,j,seq)
1219 del s[i:j] = __delslice__(s,i,j) == s[i:j] = []
1220 seq * n = __repeat__(seq, n)
1221 s1 + s2 = __concat__(s1, s2)
1222 i in s = __contains__(s, i)
1223 Mappings, general methods, plus
1224 hash(s) = __hash__(s) - hash value for dictionary references
1225 s[k]=v = __setitem__(s,k,v)
1226 del s[k] = __delitem__(s,k)
1227
1228Special informative state attributes for some types:
1229
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001230 Modules:
1231 __doc__ (string/None, R/O): doc string (<=> __dict__['__doc__'])
1232 __name__(string, R/O): module name (also in __dict__['__name__'])
1233 __dict__ (dict, R/O): module's name space
1234 __file__(string/undefined, R/O): pathname of .pyc, .pyo or .pyd (undef for
1235 modules statically linked to the interpreter)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001236
1237 Classes: [in bold: writable since 1.5.2]
1238 __doc__ (string/None, R/W): doc string (<=> __dict__['__doc__'])
Raymond Hettingere685f942003-01-26 03:29:15 +00001239 __module__ is the module name in which the class was defined
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001240 __name__(string, R/W): class name (also in __dict__['__name__'])
1241 __bases__ (tuple, R/W): parent classes
1242 __dict__ (dict, R/W): attributes (class name space)
1243
1244 Instances:
1245 __class__ (class, R/W): instance's class
1246 __dict__ (dict, R/W): attributes
Raymond Hettingere685f942003-01-26 03:29:15 +00001247
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001248 User-defined functions: [bold: writable since 1.5.2]
1249 __doc__ (string/None, R/W): doc string
1250 __name__(string, R/O): function name
1251 func_doc (R/W): same as __doc__
1252 func_name (R/O): same as __name__
1253 func_defaults (tuple/None, R/W): default args values if any
1254 func_code (code, R/W): code object representing the compiled function body
1255 func_globals (dict, R/O): ref to dictionary of func global variables
Raymond Hettingere685f942003-01-26 03:29:15 +00001256 func_dict (dict, R/W): same as __dict__ contains the namespace supporting
1257 arbitrary function attributes
1258 func_closure (R/O): None or a tuple of cells that contain bindings
1259 for the function's free variables.
1260
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001261
1262 User-defined Methods:
1263 __doc__ (string/None, R/O): doc string
1264 __name__(string, R/O): method name (same as im_func.__name__)
1265 im_class (class, R/O): class defining the method (may be a base class)
1266 im_self (instance/None, R/O): target instance object (None if unbound)
1267 im_func (function, R/O): function object
Raymond Hettingere685f942003-01-26 03:29:15 +00001268
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001269 Built-in Functions & methods:
1270 __doc__ (string/None, R/O): doc string
1271 __name__ (string, R/O): function name
1272 __self__ : [methods only] target object
Raymond Hettingere685f942003-01-26 03:29:15 +00001273
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001274 Codes:
1275 co_name (string, R/O): function name
1276 co_argcount (int, R/0): number of positional args
1277 co_nlocals (int, R/O): number of local vars (including args)
1278 co_varnames (tuple, R/O): names of local vars (starting with args)
Raymond Hettingere685f942003-01-26 03:29:15 +00001279 co_cellvars (tuple, R/O)) the names of local variables referenced by
1280 nested functions
1281 co_freevars (tuple, R/O)) names of free variables
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001282 co_code (string, R/O): sequence of bytecode instructions
1283 co_consts (tuple, R/O): litterals used by the bytecode, 1st one is
1284 fct doc (or None)
1285 co_names (tuple, R/O): names used by the bytecode
1286 co_filename (string, R/O): filename from which the code was compiled
1287 co_firstlineno (int, R/O): first line number of the function
1288 co_lnotab (string, R/O): string encoding bytecode offsets to line numbers.
1289 co_stacksize (int, R/O): required stack size (including local vars)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001290 co_flags (int, R/O): flags for the interpreter
1291 bit 2 set if fct uses "*arg" syntax
1292 bit 3 set if fct uses '**keywords' syntax
1293 Frames:
1294 f_back (frame/None, R/O): previous stack frame (toward the caller)
1295 f_code (code, R/O): code object being executed in this frame
1296 f_locals (dict, R/O): local vars
1297 f_globals (dict, R/O): global vars
1298 f_builtins (dict, R/O): built-in (intrinsic) names
1299 f_restricted (int, R/O): flag indicating whether fct is executed in
1300 restricted mode
1301 f_lineno (int, R/O): current line number
1302 f_lasti (int, R/O): precise instruction (index into bytecode)
1303 f_trace (function/None, R/W): debug hook called at start of each source line
1304 f_exc_type (Type/None, R/W): Most recent exception type
1305 f_exc_value (any, R/W): Most recent exception value
1306 f_exc_traceback (traceback/None, R/W): Most recent exception traceback
1307 Tracebacks:
1308 tb_next (frame/None, R/O): next level in stack trace (toward the frame where
1309 the exception occurred)
1310 tb_frame (frame, R/O): execution frame of the current level
1311 tb_lineno (int, R/O): line number where the exception occured
1312 tb_lasti (int, R/O): precise instruction (index into bytecode)
1313
1314 Slices:
1315 start (any/None, R/O): lowerbound
1316 stop (any/None, R/O): upperbound
1317 step (any/None, R/O): step value
1318
1319 Complex numbers:
1320 real (float, R/O): real part
1321 imag (float, R/O): imaginary part
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001322
1323
1324Important Modules
1325
1326 sys
1327
1328 Some sys variables
1329 Variable Content
1330argv The list of command line arguments passed to aPython
1331 script. sys.argv[0] is the script name.
1332builtin_module_names A list of strings giving the names of all moduleswritten
1333 in C that are linked into this interpreter.
1334check_interval How often to check for thread switches or signals(measured
1335 in number of virtual machine instructions)
1336exc_type, exc_value, Deprecated since release 1.5. Use exc_info() instead.
1337exc_traceback
1338exitfunc User can set to a parameterless fcn. It will getcalled
1339 before interpreter exits.
1340last_type, Set only when an exception not handled andinterpreter
1341last_value, prints an error. Used by debuggers.
1342last_traceback
1343maxint maximum positive value for integers
1344modules Dictionary of modules that have already been loaded.
1345path Search path for external modules. Can be modifiedby
1346 program. sys.path[0] == dir of script executing
1347platform The current platform, e.g. "sunos5", "win32"
1348ps1, ps2 prompts to use in interactive mode.
1349 File objects used for I/O. One can redirect byassigning a
1350stdin, stdout, new file object to them (or any object:.with a method
1351stderr write(string) for stdout/stderr,.with a method readline()
1352 for stdin)
1353version string containing version info about Python interpreter.
1354 (and also: copyright, dllhandle, exec_prefix, prefix)
1355version_info tuple containing Python version info - (major, minor,
1356 micro, level, serial).
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001357
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001358 Some sys functions
1359 Function Result
1360exit(n) Exits with status n. Raises SystemExit exception.(Hence can
1361 be caught and ignored by program)
Raymond Hettingere685f942003-01-26 03:29:15 +00001362getrefcount(object Returns the reference count of the object. Generally one
1363) higher than you might expect, because of object arg temp
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001364 reference.
1365setcheckinterval( Sets the interpreter's thread switching interval (in number
Skip Montanaroeec26f92003-07-02 21:38:34 +00001366interval) of virtual code instructions, default:100).
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001367settrace(func) Sets a trace function: called before each line ofcode is
1368 exited.
1369setprofile(func) Sets a profile function for performance profiling.
1370 Info on exception currently being handled; this is atuple
1371 (exc_type, exc_value, exc_traceback).Warning: assigning the
1372exc_info() traceback return value to a loca variable in a
Raymond Hettingere685f942003-01-26 03:29:15 +00001373 function handling an exception will cause a circular
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001374 reference.
1375setdefaultencoding Change default Unicode encoding - defaults to 7-bit ASCII.
1376(encoding)
1377getrecursionlimit Retrieve maximum recursion depth.
1378()
1379setrecursionlimit Set maximum recursion depth. (Defaults to 1000.)
1380()
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001381
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001382
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001383
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001384 os
1385"synonym" for whatever O/S-specific module is proper for current environment.
1386this module uses posix whenever possible.
1387(see also M.A. Lemburg's utility http://www.lemburg.com/files/python/
1388platform.py)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001389
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001390 Some os variables
1391 Variable Meaning
1392name name of O/S-specific module (e.g. "posix", "mac", "nt")
1393path O/S-specific module for path manipulations.
1394 On Unix, os.path.split() <=> posixpath.split()
1395curdir string used to represent current directory ('.')
1396pardir string used to represent parent directory ('..')
1397sep string used to separate directories ('/' or '\'). Tip: use
1398 os.path.join() to build portable paths.
1399altsep Alternate sep
1400if applicable (None
1401otherwise)
1402pathsep character used to separate search path components (as in
1403 $PATH), eg. ';' for windows.
1404linesep line separator as used in binary files, ie '\n' on Unix, '\
1405 r\n' on Dos/Win, '\r'
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001406
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001407 Some os functions
1408 Function Result
1409makedirs(path[, Recursive directory creation (create required intermediary
1410mode=0777]) dirs); os.error if fails.
1411removedirs(path) Recursive directory delete (delete intermediary empty
1412 dirs); if fails.
1413renames(old, new) Recursive directory or file renaming; os.error if fails.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001414
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001415
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001416
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001417 posix
1418don't import this module directly, import os instead !
1419(see also module: shutil for file copy & remove fcts)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001420
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001421 posix Variables
1422Variable Meaning
1423environ dictionary of environment variables, e.g.posix.environ['HOME'].
1424error exception raised on POSIX-related error.
1425 Corresponding value is tuple of errno code and perror() string.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001426
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001427 Some posix functions
1428 Function Result
1429chdir(path) Changes current directory to path.
1430chmod(path, Changes the mode of path to the numeric mode
1431mode)
1432close(fd) Closes file descriptor fd opened with posix.open.
1433_exit(n) Immediate exit, with no cleanups, no SystemExit,etc. Should use
1434 this to exit a child process.
1435execv(p, args) "Become" executable p with args args
1436getcwd() Returns a string representing the current working directory
1437getpid() Returns the current process id
1438fork() Like C's fork(). Returns 0 to child, child pid to parent.[Not
1439 on Windows]
1440kill(pid, Like C's kill [Not on Windows]
1441signal)
1442listdir(path) Lists (base)names of entries in directory path, excluding '.'
1443 and '..'
1444lseek(fd, pos, Sets current position in file fd to position pos, expressedas
1445how) an offset relative to beginning of file (how=0), tocurrent
1446 position (how=1), or to end of file (how=2)
1447mkdir(path[, Creates a directory named path with numeric mode (default 0777)
1448mode])
1449open(file, Like C's open(). Returns file descriptor. Use file object
1450flags, mode) fctsrather than this low level ones.
1451pipe() Creates a pipe. Returns pair of file descriptors (r, w) [Not on
1452 Windows].
1453popen(command, Opens a pipe to or from command. Result is a file object to
1454mode='r', read to orwrite from, as indicated by mode being 'r' or 'w'.
1455bufSize=0) Use it to catch acommand output ('r' mode) or to feed it ('w'
1456 mode).
1457remove(path) See unlink.
1458rename(src, dst Renames/moves the file or directory src to dst. [error iftarget
1459) name already exists]
1460rmdir(path) Removes the empty directory path
1461read(fd, n) Reads n bytes from file descriptor fd and return as string.
1462 Returns st_mode, st_ino, st_dev, st_nlink, st_uid,st_gid,
1463stat(path) st_size, st_atime, st_mtime, st_ctime.[st_ino, st_uid, st_gid
1464 are dummy on Windows]
1465system(command) Executes string command in a subshell. Returns exitstatus of
1466 subshell (usually 0 means OK).
1467 Returns accumulated CPU times in sec (user, system, children's
1468times() user,children's sys, elapsed real time). [3 last not on
1469 Windows]
1470unlink(path) Unlinks ("deletes") the file (not dir!) path. same as: remove
1471utime(path, ( Sets the access & modified time of the file to the given tuple
1472aTime, mTime)) of values.
1473wait() Waits for child process completion. Returns tuple ofpid,
1474 exit_status [Not on Windows]
1475waitpid(pid, Waits for process pid to complete. Returns tuple ofpid,
1476options) exit_status [Not on Windows]
1477write(fd, str) Writes str to file fd. Returns nb of bytes written.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001478
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001479
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001480
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001481 posixpath
1482Do not import this module directly, import os instead and refer to this module
1483as os.path. (e.g. os.path.exists(p)) !
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001484
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001485 Some posixpath functions
1486 Function Result
1487abspath(p) Returns absolute path for path p, taking current working dir in
1488 account.
1489dirname/
1490basename(p directory and name parts of the path p. See also split.
1491)
1492exists(p) True if string p is an existing path (file or directory)
1493expanduser Returns string that is (a copy of) p with "~" expansion done.
1494(p)
1495expandvars Returns string that is (a copy of) p with environment vars expanded.
1496(p) [Windows: case significant; must use Unix: $var notation, not %var%]
1497getsize( return the size in bytes of filename. raise os.error.
1498filename)
1499getmtime( return last modification time of filename (integer nb of seconds
1500filename) since epoch).
1501getatime( return last access time of filename (integer nb of seconds since
1502filename) epoch).
1503isabs(p) True if string p is an absolute path.
1504isdir(p) True if string p is a directory.
1505islink(p) True if string p is a symbolic link.
1506ismount(p) True if string p is a mount point [true for all dirs on Windows].
1507join(p[,q Joins one or more path components intelligently.
1508[,...]])
1509 Splits p into (head, tail) where tail is lastpathname component and
1510split(p) <head> is everything leadingup to that. <=> (dirname(p), basename
1511 (p))
1512splitdrive Splits path p in a pair ('drive:', tail) [Windows]
1513(p)
1514splitext(p Splits into (root, ext) where last comp of root contains no periods
1515) and ext is empty or startswith a period.
1516 Calls the function visit with arguments(arg, dirname, names) for
1517 each directory recursively inthe directory tree rooted at p
1518walk(p, (including p itself if it's a dir)The argument dirname specifies the
1519visit, arg visited directory, the argumentnames lists the files in the
1520) directory. The visit function maymodify names to influence the set
1521 of directories visited belowdirname, e.g., to avoid visiting certain
1522 parts of the tree.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001523
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001524
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001525
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001526 shutil
1527high-level file operations (copying, deleting).
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001528
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001529 Main shutil functions
1530 Function Result
1531copy(src, dst) Copies the contents of file src to file dst, retaining file
1532 permissions.
1533copytree(src, dst Recursively copies an entire directory tree rooted at src
1534[, symlinks]) into dst (which should not already exist). If symlinks is
1535 true, links insrc are kept as such in dst.
1536rmtree(path[, Deletes an entire directory tree, ignoring errors if
1537ignore_errors[, ignore_errors true,or calling onerror(func, path,
1538onerror]]) sys.exc_info()) if supplied with
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001539
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001540(and also: copyfile, copymode, copystat, copy2)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001541
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001542time
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001543
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001544 Variables
1545Variable Meaning
1546altzone signed offset of local DST timezone in sec west of the 0th meridian.
1547daylight nonzero if a DST timezone is specified
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001548
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001549 Functions
1550 Function Result
1551time() return a float representing UTC time in seconds since the epoch.
1552gmtime(secs), return a tuple representing time : (year aaaa, month(1-12),day
1553localtime( (1-31), hour(0-23), minute(0-59), second(0-59), weekday(0-6, 0 is
1554secs) monday), Julian day(1-366), daylight flag(-1,0 or 1))
1555asctime(
1556timeTuple),
1557strftime(
1558format, return a formated string representing time.
1559timeTuple)
1560mktime(tuple) inverse of localtime(). Return a float.
1561strptime( parse a formated string representing time, return tuple as in
1562string[, gmtime().
1563format])
1564sleep(secs) Suspend execution for <secs> seconds. <secs> can be a float.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001565
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001566and also: clock, ctime.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001567
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001568 string
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001569
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001570As of Python 2.0, much (though not all) of the functionality provided by the
1571string module have been superseded by built-in string methods - see Operations
1572on strings for details.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001573
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001574 Some string variables
1575 Variable Meaning
1576digits The string '0123456789'
1577hexdigits, octdigits legal hexadecimal & octal digits
1578letters, uppercase, lowercase, Strings containing the appropriate
1579whitespace characters
1580index_error Exception raised by index() if substr not
1581 found.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001582
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001583 Some string functions
1584 Function Result
1585expandtabs(s, returns a copy of string <s> with tabs expanded.
1586tabSize)
1587find/rfind(s, sub Return the lowest/highest index in <s> where the substring
1588[, start=0[, end= <sub> is found such that <sub> is wholly contained ins
15890]) [start:end]. Return -1 if <sub> not found.
1590ljust/rjust/center Return a copy of string <s> left/right justified/centerd in
1591(s, width) afield of given width, padded with spaces. <s> is
1592 nevertruncated.
1593lower/upper(s) Return a string that is (a copy of) <s> in lowercase/
1594 uppercase
1595split(s[, sep= Return a list containing the words of the string <s>,using
1596whitespace[, the string <sep> as a separator.
1597maxsplit=0]])
1598join(words[, sep=' Concatenate a list or tuple of words with
1599']) interveningseparators; inverse of split.
1600replace(s, old, Returns a copy of string <s> with all occurences of
1601new[, maxsplit=0] substring<old> replaced by <new>. Limits to <maxsplit>
1602 firstsubstitutions if specified.
1603strip(s) Return a string that is (a copy of) <s> without leadingand
1604 trailing whitespace. see also lstrip, rstrip.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001605
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001606
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001607
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001608 re (sre)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001609
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001610Handles Unicode strings. Implemented in new module sre, re now a mere front-end
1611for compatibility.
1612Patterns are specified as strings. Tip: Use raw strings (e.g. r'\w*') to
1613litteralize backslashes.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001614
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001615
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001616 Regular expression syntax
1617 Form Description
1618. matches any character (including newline if DOTALL flag specified)
1619^ matches start of the string (of every line in MULTILINE mode)
1620$ matches end of the string (of every line in MULTILINE mode)
1621* 0 or more of preceding regular expression (as many as possible)
1622+ 1 or more of preceding regular expression (as many as possible)
1623? 0 or 1 occurence of preceding regular expression
1624*?, +?, ?? Same as *, + and ? but matches as few characters as possible
1625{m,n} matches from m to n repetitions of preceding RE
1626{m,n}? idem, attempting to match as few repetitions as possible
1627[ ] defines character set: e.g. '[a-zA-Z]' to match all letters(see also
1628 \w \S)
1629[^ ] defines complemented character set: matches if char is NOT in set
1630 escapes special chars '*?+&$|()' and introduces special sequences
1631\ (see below). Due to Python string rules, write as '\\' orr'\' in the
1632 pattern string.
1633\\ matches a litteral '\'; due to Python string rules, write as '\\\\
1634 'in pattern string, or better using raw string: r'\\'.
1635| specifies alternative: 'foo|bar' matches 'foo' or 'bar'
1636(...) matches any RE inside (), and delimits a group.
1637(?:...) idem but doesn't delimit a group.
1638 matches if ... matches next, but doesn't consume any of the string
1639(?=...) e.g. 'Isaac (?=Asimov)' matches 'Isaac' only if followed by
1640 'Asimov'.
1641(?!...) matches if ... doesn't match next. Negative of (?=...)
1642(?P<name matches any RE inside (), and delimits a named group. (e.g. r'(?P
1643>...) <id>[a-zA-Z_]\w*)' defines a group named id)
1644(?P=name) matches whatever text was matched by the earlier group named name.
1645(?#...) A comment; ignored.
1646(?letter) letter is one of 'i','L', 'm', 's', 'x'. Set the corresponding flags
1647 (re.I, re.L, re.M, re.S, re.X) for the entire RE.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001648
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001649 Special sequences
1650Sequence Description
1651number matches content of the group of the same number; groups are numbered
1652 starting from 1
1653\A matches only at the start of the string
1654\b empty str at beg or end of word: '\bis\b' matches 'is', but not 'his'
1655\B empty str NOT at beginning or end of word
1656\d any decimal digit (<=> [0-9])
1657\D any non-decimal digit char (<=> [^O-9])
1658\s any whitespace char (<=> [ \t\n\r\f\v])
1659\S any non-whitespace char (<=> [^ \t\n\r\f\v])
1660\w any alphaNumeric char (depends on LOCALE flag)
1661\W any non-alphaNumeric char (depends on LOCALE flag)
1662\Z matches only at the end of the string
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001663
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001664 Variables
1665Variable Meaning
1666error Exception when pattern string isn't a valid regexp.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001667
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001668 Functions
1669 Function Result
1670 Compile a RE pattern string into a regular expression object.
1671 Flags (combinable by |):
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001672
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001673 I or IGNORECASE or (?i)
1674 case insensitive matching
1675compile( L or LOCALE or (?L)
1676pattern[, make \w, \W, \b, \B dependent on thecurrent locale
1677flags=0]) M or MULTILINE or (?m)
1678 matches every new line and not onlystart/end of the whole
1679 string
1680 S or DOTALL or (?s)
1681 '.' matches ALL chars, including newline
1682 X or VERBOSE or (?x)
1683 Ignores whitespace outside character sets
1684escape(string) return (a copy of) string with all non-alphanumerics
1685 backslashed.
1686match(pattern, if 0 or more chars at beginning of <string> match the RE pattern
1687string[, flags string,return a corresponding MatchObject instance, or None if
1688]) no match.
1689search(pattern scan thru <string> for a location matching <pattern>, return
1690, string[, acorresponding MatchObject instance, or None if no match.
1691flags])
1692split(pattern, split <string> by occurrences of <pattern>. If capturing () are
1693string[, used inpattern, then occurrences of patterns or subpatterns are
1694maxsplit=0]) also returned.
1695findall( return a list of non-overlapping matches in <pattern>, either a
1696pattern, list ofgroups or a list of tuples if the pattern has more than 1
1697string) group.
1698 return string obtained by replacing the (<count> first) lefmost
1699sub(pattern, non-overlapping occurrences of <pattern> (a string or a RE
1700repl, string[, object) in <string>by <repl>; <repl> can be a string or a fct
1701count=0]) called with a single MatchObj arg, which must return the
1702 replacement string.
1703subn(pattern,
1704repl, string[, same as sub(), but returns a tuple (newString, numberOfSubsMade)
1705count=0])
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001706
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001707Regular Expression Objects
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001708
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001709
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001710(RE objects are returned by the compile fct)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001711
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001712 re object attributes
1713Attribute Descrition
1714flags flags arg used when RE obj was compiled, or 0 if none provided
1715groupindex dictionary of {group name: group number} in pattern
1716pattern pattern string from which RE obj was compiled
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001717
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001718 re object methods
1719 Method Result
1720 If zero or more characters at the beginning of string match this
1721 regular expression, return a corresponding MatchObject instance.
1722 Return None if the string does not match the pattern; note that
1723 this is different from a zero-length match.
1724 The optional second parameter pos gives an index in the string
1725match( where the search is to start; it defaults to 0. This is not
1726string[, completely equivalent to slicing the string; the '' pattern
1727pos][, character matches at the real beginning of the string and at
1728endpos]) positions just after a newline, but not necessarily at the index
1729 where the search is to start.
1730 The optional parameter endpos limits how far the string will be
1731 searched; it will be as if the string is endpos characters long, so
1732 only the characters from pos to endpos will be searched for a
1733 match.
1734 Scan through string looking for a location where this regular
1735search( expression produces a match, and return a corresponding MatchObject
1736string[, instance. Return None if no position in the string matches the
1737pos][, pattern; note that this is different from finding a zero-length
1738endpos]) match at some point in the string.
1739 The optional pos and endpos parameters have the same meaning as for
1740 the match() method.
1741split(
1742string[, Identical to the split() function, using the compiled pattern.
1743maxsplit=
17440])
1745findall( Identical to the findall() function, using the compiled pattern.
1746string)
1747sub(repl,
1748string[, Identical to the sub() function, using the compiled pattern.
1749count=0])
1750subn(repl,
1751string[, Identical to the subn() function, using the compiled pattern.
1752count=0])
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001753
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001754Match Objects
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001755
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001756
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001757(Match objects are returned by the match & search functions)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001758
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001759 Match object attributes
1760Attribute Description
1761pos value of pos passed to search or match functions; index intostring at
1762 which RE engine started search.
1763endpos value of endpos passed to search or match functions; index intostring
1764 beyond which RE engine won't go.
1765re RE object whose match or search fct produced this MatchObj instance
1766string string passed to match() or search()
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001767
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001768 Match object functions
1769Function Result
1770 returns one or more groups of the match. If one arg, result is a
1771group([g1 string;if multiple args, result is a tuple with one item per arg. If
1772, g2, gi is 0,return value is entire matching string; if 1 <= gi <= 99,
1773...]) returnstring matching group #gi (or None if no such group); gi may
1774 also bea group name.
1775 returns a tuple of all groups of the match; groups not
1776groups() participatingto the match have a value of None. Returns a string
1777 instead of tupleif len(tuple)=1
1778start(
1779group), returns indices of start & end of substring matched by group (or
1780end(group Noneif group exists but doesn't contribute to the match)
1781)
1782span( returns the 2-tuple (start(group), end(group)); can be (None, None)if
1783group) group didn't contibute to the match.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001784
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001785
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001786
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001787 math
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001788
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001789Variables:
1790pi
1791e
1792Functions (see ordinary C man pages for info):
1793acos(x)
1794asin(x)
1795atan(x)
1796atan2(x, y)
1797ceil(x)
1798cos(x)
1799cosh(x)
Raymond Hettingere685f942003-01-26 03:29:15 +00001800degrees(x)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001801exp(x)
1802fabs(x)
1803floor(x)
1804fmod(x, y)
1805frexp(x) -- Unlike C: (float, int) = frexp(float)
1806ldexp(x, y)
Raymond Hettingere685f942003-01-26 03:29:15 +00001807log(x [,base])
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001808log10(x)
1809modf(x) -- Unlike C: (float, float) = modf(float)
1810pow(x, y)
Raymond Hettingere685f942003-01-26 03:29:15 +00001811radians(x)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001812sin(x)
1813sinh(x)
1814sqrt(x)
1815tan(x)
1816tanh(x)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001817
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001818 getopt
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001819
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001820Functions:
1821getopt(list, optstr) -- Similar to C. <optstr> is option
1822 letters to look for. Put ':' after letter
1823 if option takes arg. E.g.
1824 # invocation was "python test.py -c hi -a arg1 arg2"
1825 opts, args = getopt.getopt(sys.argv[1:], 'ab:c:')
1826 # opts would be
1827 [('-c', 'hi'), ('-a', '')]
1828 # args would be
1829 ['arg1', 'arg2']
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001830
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001831
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001832List of modules and packages in base distribution
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001833
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001834(built-ins and content of python Lib directory)
1835(Python NT distribution, may be slightly different in other distributions)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00001836
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001837 Standard library modules
1838 Operation Result
1839aifc Stuff to parse AIFF-C and AIFF files.
1840anydbm Generic interface to all dbm clones. (dbhash, gdbm,
1841 dbm,dumbdbm)
1842asynchat Support for 'chat' style protocols
1843asyncore Asynchronous File I/O (in select style)
1844atexit Register functions to be called at exit of Python interpreter.
1845audiodev Audio support for a few platforms.
1846base64 Conversions to/from base64 RFC-MIME transport encoding .
1847BaseHTTPServer Base class forhttp services.
1848Bastion "Bastionification" utility (control access to instance vars)
1849bdb A generic Python debugger base class.
1850binhex Macintosh binhex compression/decompression.
1851bisect List bisection algorithms.
Raymond Hettingere685f942003-01-26 03:29:15 +00001852bz2 Support for bz2 compression/decompression.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001853calendar Calendar printing functions.
1854cgi Wraps the WWW Forms Common Gateway Interface (CGI).
Raymond Hettingere685f942003-01-26 03:29:15 +00001855cgitb Utility for handling CGI tracebacks.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001856CGIHTTPServer CGI http services.
1857cmd A generic class to build line-oriented command interpreters.
Raymond Hettingere685f942003-01-26 03:29:15 +00001858datetime Basic date and time types.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001859code Utilities needed to emulate Python's interactive interpreter
1860codecs Lookup existing Unicode encodings and register new ones.
1861colorsys Conversion functions between RGB and other color systems.
1862commands Tools for executing UNIX commands .
1863compileall Force "compilation" of all .py files in a directory.
1864ConfigParser Configuration file parser (much like windows .ini files)
1865copy Generic shallow and deep copying operations.
1866copy_reg Helper to provide extensibility for pickle/cPickle.
Raymond Hettingerca60cac2003-07-12 23:55:57 +00001867csv Read and write files with comma separated values.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001868dbhash (g)dbm-compatible interface to bsdhash.hashopen.
1869dircache Sorted list of files in a dir, using a cache.
1870[DEL:dircmp:DEL] [DEL:Defines a class to build directory diff tools on.:DEL]
Raymond Hettingere685f942003-01-26 03:29:15 +00001871difflib Tool for creating delta between sequences.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001872dis Bytecode disassembler.
1873distutils Package installation system.
Raymond Hettingere685f942003-01-26 03:29:15 +00001874doctest Tool for running and verifying tests inside doc strings.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001875dospath Common operations on DOS pathnames.
1876dumbdbm A dumb and slow but simple dbm clone.
1877[DEL:dump:DEL] [DEL:Print python code that reconstructs a variable.:DEL]
Raymond Hettingere685f942003-01-26 03:29:15 +00001878email Comprehensive support for internet email.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001879exceptions Class based built-in exception hierarchy.
1880filecmp File comparison.
1881fileinput Helper class to quickly write a loop over all standard input
1882 files.
1883[DEL:find:DEL] [DEL:Find files directory hierarchy matching a pattern.:DEL]
1884fnmatch Filename matching with shell patterns.
1885formatter A test formatter.
1886fpformat General floating point formatting functions.
1887ftplib An FTP client class. Based on RFC 959.
1888gc Perform garbacge collection, obtain GC debug stats, and tune
1889 GC parameters.
1890getopt Standard command line processing. See also ftp://
1891 www.pauahtun.org/pub/getargspy.zip
1892getpass Utilities to get a password and/or the current user name.
1893glob filename globbing.
1894gopherlib Gopher protocol client interface.
1895[DEL:grep:DEL] [DEL:'grep' utilities.:DEL]
1896gzip Read & write gzipped files.
Raymond Hettingere685f942003-01-26 03:29:15 +00001897heapq Priority queue implemented using lists organized as heaps.
1898HMAC Keyed-Hashing for Message Authentication -- RFC 2104.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001899htmlentitydefs Proposed entity definitions for HTML.
1900htmllib HTML parsing utilities.
Raymond Hettingere685f942003-01-26 03:29:15 +00001901HTMLParser A parser for HTML and XHTML.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001902httplib HTTP client class.
1903ihooks Hooks into the "import" mechanism.
1904imaplib IMAP4 client.Based on RFC 2060.
1905imghdr Recognizing image files based on their first few bytes.
1906imputil Privides a way of writing customised import hooks.
Raymond Hettingere685f942003-01-26 03:29:15 +00001907inspect Tool for probing live Python objects.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001908keyword List of Python keywords.
1909knee A Python re-implementation of hierarchical module import.
1910linecache Cache lines from files.
1911linuxaudiodev Lunix /dev/audio support.
1912locale Support for number formatting using the current locale
1913 settings.
Raymond Hettingere685f942003-01-26 03:29:15 +00001914logging Python logging facility.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001915macpath Pathname (or related) operations for the Macintosh.
1916macurl2path Mac specific module for conversion between pathnames and URLs.
1917mailbox A class to handle a unix-style or mmdf-style mailbox.
1918mailcap Mailcap file handling (RFC 1524).
1919mhlib MH (mailbox) interface.
1920mimetools Various tools used by MIME-reading or MIME-writing programs.
1921mimetypes Guess the MIME type of a file.
1922MimeWriter Generic MIME writer.
1923mimify Mimification and unmimification of mail messages.
1924mmap Interface to memory-mapped files - they behave like mutable
1925 strings./font>
1926multifile Class to make multi-file messages easier to handle.
1927mutex Mutual exclusion -- for use with module sched.
1928netrc
1929nntplib An NNTP client class. Based on RFC 977.
1930ntpath Common operations on DOS pathnames.
1931nturl2path Mac specific module for conversion between pathnames and URLs.
Raymond Hettingere685f942003-01-26 03:29:15 +00001932optparse A comprehensive tool for processing command line options.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001933os Either mac, dos or posix depending system.
1934[DEL:packmail: [DEL:Create a self-unpacking shell archive.:DEL]
1935DEL]
1936pdb A Python debugger.
1937pickle Pickling (save and restore) of Python objects (a faster
1938 Cimplementation exists in built-in module: cPickle).
1939pipes Conversion pipeline templates.
Raymond Hettingere685f942003-01-26 03:29:15 +00001940pkgunil Utilities for working with Python packages.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001941popen2 variations on pipe open.
1942poplib A POP3 client class. Based on the J. Myers POP3 draft.
1943posixfile Extended (posix) file operations.
1944posixpath Common operations on POSIX pathnames.
1945pprint Support to pretty-print lists, tuples, & dictionaries
1946 recursively.
1947profile Class for profiling python code.
1948pstats Class for printing reports on profiled python code.
Raymond Hettingere685f942003-01-26 03:29:15 +00001949pydoc Utility for generating documentation from source files.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001950pty Pseudo terminal utilities.
1951pyexpat Interface to the Expay XML parser.
1952py_compile Routine to "compile" a .py file to a .pyc file.
1953pyclbr Parse a Python file and retrieve classes and methods.
1954Queue A multi-producer, multi-consumer queue.
1955quopri Conversions to/from quoted-printable transport encoding.
1956rand Don't use unless you want compatibility with C's rand().
Raymond Hettinger5a772d32003-01-25 22:35:42 +00001957random Random variable generators
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001958re Regular Expressions.
1959reconvert Convert old ("regex") regular expressions to new syntax
1960 ("re").
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001961repr Redo repr() but with limits on most sizes.
1962rexec Restricted execution facilities ("safe" exec, eval, etc).
1963rfc822 RFC-822 message manipulation class.
1964rlcompleter Word completion for GNU readline 2.0.
1965robotparser Parse robot.txt files, useful for web spiders.
1966sched A generally useful event scheduler class.
Raymond Hettingere685f942003-01-26 03:29:15 +00001967sets Module for a set datatype.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001968sgmllib A parser for SGML.
1969shelve Manage shelves of pickled objects.
1970shlex Lexical analyzer class for simple shell-like syntaxes.
1971shutil Utility functions usable in a shell-like program.
1972SimpleHTTPServer Simple extension to base http class
1973site Append module search paths for third-party packages to
1974 sys.path.
1975smtplib SMTP Client class (RFC 821)
1976sndhdr Several routines that help recognizing sound.
1977SocketServer Generic socket server classes.
1978stat Constants and functions for interpreting stat/lstat struct.
1979statcache Maintain a cache of file stats.
1980statvfs Constants for interpreting statvfs struct as returned by
1981 os.statvfs()and os.fstatvfs() (if they exist).
1982string A collection of string operations.
1983StringIO File-like objects that read/write a string buffer (a fasterC
1984 implementation exists in built-in module: cStringIO).
1985sunau Stuff to parse Sun and NeXT audio files.
1986sunaudio Interpret sun audio headers.
1987symbol Non-terminal symbols of Python grammar (from "graminit.h").
1988tabnanny,/font> Check Python source for ambiguous indentation.
Raymond Hettingere685f942003-01-26 03:29:15 +00001989tarfile Facility for reading and writing to the *nix tarfile format.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001990telnetlib TELNET client class. Based on RFC 854.
1991tempfile Temporary file name allocation.
Raymond Hettingere685f942003-01-26 03:29:15 +00001992textwrap Object for wrapping and filling text.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00001993threading Proposed new higher-level threading interfaces
1994threading_api (doc of the threading module)
1995toaiff Convert "arbitrary" sound files to AIFF files .
1996token Tokens (from "token.h").
1997tokenize Compiles a regular expression that recognizes Python tokens.
1998traceback Format and print Python stack traces.
1999tty Terminal utilities.
2000turtle LogoMation-like turtle graphics
2001types Define names for all type symbols in the std interpreter.
2002tzparse Parse a timezone specification.
2003unicodedata Interface to unicode properties.
2004urllib Open an arbitrary URL.
2005urlparse Parse URLs according to latest draft of standard.
2006user Hook to allow user-specified customization code to run.
2007UserDict A wrapper to allow subclassing of built-in dict class.
2008UserList A wrapper to allow subclassing of built-in list class.
2009UserString A wrapper to allow subclassing of built-in string class.
2010[DEL:util:DEL] [DEL:some useful functions that don't fit elsewhere !!:DEL]
2011uu UUencode/UUdecode.
Raymond Hettingere685f942003-01-26 03:29:15 +00002012unittest Utilities for implementing unit testing.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002013wave Stuff to parse WAVE files.
Raymond Hettingere685f942003-01-26 03:29:15 +00002014weakref Tools for creating and managing weakly referenced objects.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002015webbrowser Platform independent URL launcher.
2016[DEL:whatsound: [DEL:Several routines that help recognizing sound files.:DEL]
2017DEL]
2018whichdb Guess which db package to use to open a db file.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002019xdrlib Implements (a subset of) Sun XDR (eXternal Data
2020 Representation)
2021xmllib A parser for XML, using the derived class as static DTD.
2022xml.dom Classes for processing XML using the Document Object Model.
2023xml.sax Classes for processing XML using the SAX API.
Raymond Hettingere685f942003-01-26 03:29:15 +00002024xmlrpclib Support for remote procedure calls using XML.
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002025zipfile Read & write PK zipped files.
2026[DEL:zmod:DEL] [DEL:Demonstration of abstruse mathematical concepts.:DEL]
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002027
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002028
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002029
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002030* Built-ins *
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002031
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002032 sys Interpreter state vars and functions
2033 __built-in__ Access to all built-in python identifiers
2034 __main__ Scope of the interpreters main program, script or stdin
2035 array Obj efficiently representing arrays of basic values
2036 math Math functions of C standard
Raymond Hettingere685f942003-01-26 03:29:15 +00002037 time Time-related functions (also the newer datetime module)
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002038 regex Regular expression matching operations
2039 marshal Read and write some python values in binary format
2040 struct Convert between python values and C structs
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002041
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002042* Standard *
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002043
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002044 getopt Parse cmd line args in sys.argv. A la UNIX 'getopt'.
2045 os A more portable interface to OS dependent functionality
2046 re Functions useful for working with regular expressions
2047 string Useful string and characters functions and exceptions
Raymond Hettingere685f942003-01-26 03:29:15 +00002048 random Mersenne Twister pseudo-random number generator
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002049 thread Low-level primitives for working with process threads
2050 threading idem, new recommanded interface.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002051
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002052* Unix/Posix *
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002053
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002054 dbm Interface to Unix ndbm database library
2055 grp Interface to Unix group database
2056 posix OS functionality standardized by C and POSIX standards
2057 posixpath POSIX pathname functions
2058 pwd Access to the Unix password database
2059 select Access to Unix select multiplex file synchronization
2060 socket Access to BSD socket interface
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002061
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002062* Tk User-interface Toolkit *
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002063
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002064 tkinter Main interface to Tk
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002065
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002066* Multimedia *
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002067
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002068 audioop Useful operations on sound fragments
2069 imageop Useful operations on images
2070 jpeg Access to jpeg image compressor and decompressor
2071 rgbimg Access SGI imglib image files
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002072
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002073* Cryptographic Extensions *
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002074
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002075 md5 Interface to RSA's MD5 message digest algorithm
2076 mpz Interface to int part of GNU multiple precision library
Raymond Hettingere685f942003-01-26 03:29:15 +00002077 rotor Implementation of a rotor-based encryption algorithm
2078 HMAC Keyed-Hashing for Message Authentication -- RFC 2104.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002079
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002080* Stdwin * Standard Window System
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002081
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002082 stdwin Standard Window System interface
2083 stdwinevents Stdwin event, command, and selection constants
2084 rect Rectangle manipulation operations
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002085
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002086* SGI IRIX * (4 & 5)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002087
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002088 al SGI audio facilities
2089 AL al constants
2090 fl Interface to FORMS library
2091 FL fl constants
2092 flp Functions for form designer
2093 fm Access to font manager library
2094 gl Access to graphics library
2095 GL Constants for gl
2096 DEVICE More constants for gl
2097 imgfile Imglib image file interface
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002098
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002099* Suns *
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002100
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002101 sunaudiodev Access to sun audio interface
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002102
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002103
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002104Workspace exploration and idiom hints
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002105
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002106 dir(<module>) list functions, variables in <module>
2107 dir() get object keys, defaults to local name space
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002108 if __name__ == '__main__': main() invoke main if running as script
2109 map(None, lst1, lst2, ...) merge lists
2110 b = a[:] create copy of seq structure
2111 _ in interactive mode, is last value printed
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002112
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002113
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002114
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002115
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002116
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002117
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002118
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002119Python Mode for Emacs
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002120
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002121(Not revised, possibly not up to date)
2122Type C-c ? when in python-mode for extensive help.
2123INDENTATION
2124Primarily for entering new code:
2125 TAB indent line appropriately
2126 LFD insert newline, then indent
2127 DEL reduce indentation, or delete single character
2128Primarily for reindenting existing code:
2129 C-c : guess py-indent-offset from file content; change locally
2130 C-u C-c : ditto, but change globally
2131 C-c TAB reindent region to match its context
2132 C-c < shift region left by py-indent-offset
2133 C-c > shift region right by py-indent-offset
2134MARKING & MANIPULATING REGIONS OF CODE
2135C-c C-b mark block of lines
2136M-C-h mark smallest enclosing def
2137C-u M-C-h mark smallest enclosing class
2138C-c # comment out region of code
2139C-u C-c # uncomment region of code
2140MOVING POINT
2141C-c C-p move to statement preceding point
2142C-c C-n move to statement following point
2143C-c C-u move up to start of current block
2144M-C-a move to start of def
2145C-u M-C-a move to start of class
2146M-C-e move to end of def
2147C-u M-C-e move to end of class
2148EXECUTING PYTHON CODE
2149C-c C-c sends the entire buffer to the Python interpreter
2150C-c | sends the current region
2151C-c ! starts a Python interpreter window; this will be used by
2152 subsequent C-c C-c or C-c | commands
Raymond Hettingere685f942003-01-26 03:29:15 +00002153C-c C-w runs PyChecker
2154
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002155VARIABLES
2156py-indent-offset indentation increment
2157py-block-comment-prefix comment string used by py-comment-region
2158py-python-command shell command to invoke Python interpreter
2159py-scroll-process-buffer t means always scroll Python process buffer
2160py-temp-directory directory used for temp files (if needed)
2161py-beep-if-tab-change ring the bell if tab-width is changed
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002162
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002163
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002164The Python Debugger
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002165
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002166(Not revised, possibly not up to date, see 1.5.2 Library Ref section 9.1; in 1.5.2, you may also use debugger integrated in IDLE)
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002167
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002168Accessing
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002169
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002170import pdb (it's a module written in Python)
2171 -- defines functions :
2172 run(statement[,globals[, locals]])
2173 -- execute statement string under debugger control, with optional
2174 global & local environment.
2175 runeval(expression[,globals[, locals]])
2176 -- same as run, but evaluate expression and return value.
2177 runcall(function[, argument, ...])
2178 -- run function object with given arg(s)
2179 pm() -- run postmortem on last exception (like debugging a core file)
2180 post_mortem(t)
2181 -- run postmortem on traceback object <t>
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002182
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002183 -- defines class Pdb :
2184 use Pdb to create reusable debugger objects. Object
2185 preserves state (i.e. break points) between calls.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002186
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002187 runs until a breakpoint hit, exception, or end of program
2188 If exception, variable '__exception__' holds (exception,value).
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002189
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002190Commands
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002191
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002192h, help
2193 brief reminder of commands
2194b, break [<arg>]
2195 if <arg> numeric, break at line <arg> in current file
2196 if <arg> is function object, break on entry to fcn <arg>
2197 if no arg, list breakpoints
2198cl, clear [<arg>]
2199 if <arg> numeric, clear breakpoint at <arg> in current file
2200 if no arg, clear all breakpoints after confirmation
2201w, where
2202 print current call stack
2203u, up
2204 move up one stack frame (to top-level caller)
2205d, down
2206 move down one stack frame
2207s, step
2208 advance one line in the program, stepping into calls
2209n, next
2210 advance one line, stepping over calls
2211r, return
2212 continue execution until current function returns
2213 (return value is saved in variable "__return__", which
2214 can be printed or manipulated from debugger)
2215c, continue
2216 continue until next breakpoint
Raymond Hettingere685f942003-01-26 03:29:15 +00002217j, jump lineno
2218 Set the next line that will be executed
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002219a, args
2220 print args to current function
2221rv, retval
2222 prints return value from last function that returned
2223p, print <arg>
2224 prints value of <arg> in current stack frame
2225l, list [<first> [, <last>]]
2226 List source code for the current file.
2227 Without arguments, list 11 lines around the current line
2228 or continue the previous listing.
2229 With one argument, list 11 lines starting at that line.
2230 With two arguments, list the given range;
2231 if the second argument is less than the first, it is a count.
2232whatis <arg>
2233 prints type of <arg>
2234!
2235 executes rest of line as a Python statement in the current stack frame
2236q quit
2237 immediately stop execution and leave debugger
2238<return>
2239 executes last command again
2240Any input debugger doesn't recognize as a command is assumed to be a
2241Python statement to execute in the current stack frame, the same way
2242the exclamation mark ("!") command does.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002243
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002244Example
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002245
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002246(1394) python
2247Python 1.0.3 (Sep 26 1994)
2248Copyright 1991-1994 Stichting Mathematisch Centrum, Amsterdam
2249>>> import rm
2250>>> rm.run()
2251Traceback (innermost last):
2252 File "<stdin>", line 1
2253 File "./rm.py", line 7
2254 x = div(3)
2255 File "./rm.py", line 2
2256 return a / r
2257ZeroDivisionError: integer division or modulo
2258>>> import pdb
2259>>> pdb.pm()
2260> ./rm.py(2)div: return a / r
2261(Pdb) list
2262 1 def div(a):
2263 2 -> return a / r
2264 3
2265 4 def run():
2266 5 global r
2267 6 r = 0
2268 7 x = div(3)
2269 8 print x
2270[EOF]
2271(Pdb) print r
22720
2273(Pdb) q
2274>>> pdb.runcall(rm.run)
2275etc.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002276
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002277Quirks
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002278
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002279Breakpoints are stored as filename, line number tuples. If a module is reloaded
2280after editing, any remembered breakpoints are likely to be wrong.
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002281
Andrew M. Kuchling13423f32001-08-06 17:43:49 +00002282Always single-steps through top-most stack frame. That is, "c" acts like "n".
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002283
Guido van Rossumc8180cc1994-08-05 15:57:31 +00002284