Tim Peters | d66595f | 2001-02-04 03:09:53 +0000 | [diff] [blame] | 1 | What's New in Python 2.1 alpha 507? |
| 2 | =================================== |
| 3 | |
| 4 | Core language, builtins, and interpreter |
| 5 | |
| 6 | Standard library |
| 7 | |
| 8 | Windows changes |
| 9 | |
| 10 | - Build: Subproject _test (effectively) renamed to _testcapi. |
| 11 | |
Tim Peters | d7b5e88 | 2001-01-25 03:36:26 +0000 | [diff] [blame] | 12 | What's New in Python 2.1 alpha 2? |
| 13 | ================================= |
Tim Peters | 40ead76 | 2001-01-27 05:35:26 +0000 | [diff] [blame] | 14 | |
Tim Peters | d7b5e88 | 2001-01-25 03:36:26 +0000 | [diff] [blame] | 15 | Core language, builtins, and interpreter |
| 16 | |
Jeremy Hylton | 4589bd8 | 2001-02-01 20:38:45 +0000 | [diff] [blame] | 17 | - Scopes nest. If a name is used in a function or class, but is not |
| 18 | local, the definition in the nearest enclosing function scope will |
| 19 | be used. One consequence of this change is that lambda statements |
| 20 | could reference variables in the namespaces where the lambda is |
| 21 | defined. In some unusual cases, this change will break code. |
| 22 | |
| 23 | In all previous version of Python, names were resolved in exactly |
| 24 | three namespaces -- the local namespace, the global namespace, and |
Jeremy Hylton | d6b1cf9 | 2001-02-02 20:06:28 +0000 | [diff] [blame] | 25 | the builtin namespace. According to this old definition, if a |
Jeremy Hylton | 4589bd8 | 2001-02-01 20:38:45 +0000 | [diff] [blame] | 26 | function A is defined within a function B, the names bound in B are |
| 27 | not visible in A. The new rules make names bound in B visible in A, |
| 28 | unless A contains a name binding that hides the binding in B. |
| 29 | |
| 30 | Section 4.1 of the reference manual describes the new scoping rules |
| 31 | in detail. The test script in Lib/test/test_scope.py demonstrates |
| 32 | some of the effects of the change. |
| 33 | |
| 34 | The new rules will cause existing code to break if it defines nested |
| 35 | functions where an outer function has local variables with the same |
| 36 | name as globals or builtins used by the inner function. Example: |
| 37 | |
| 38 | def munge(str): |
| 39 | def helper(x): |
| 40 | return str(x) |
| 41 | if type(str) != type(''): |
| 42 | str = helper(str) |
| 43 | return str.strip() |
| 44 | |
| 45 | Under the old rules, the name str in helper() is bound to the |
| 46 | builtin function str(). Under the new rules, it will be bound to |
| 47 | the argument named str and an error will occur when helper() is |
| 48 | called. |
| 49 | |
Jeremy Hylton | d6b1cf9 | 2001-02-02 20:06:28 +0000 | [diff] [blame] | 50 | - The compiler will report a SyntaxError if "from ... import *" occurs |
| 51 | in a function or class scope. The language reference has documented |
| 52 | that this case is illegal, but the compiler never checked for it. |
| 53 | The recent introduction of nested scope makes the meaning of this |
| 54 | form of name binding ambiguous. In a future release, the compiler |
| 55 | may allow this form when there is no possibility of ambiguity. |
| 56 | |
Tim Peters | 40ead76 | 2001-01-27 05:35:26 +0000 | [diff] [blame] | 57 | - repr(string) is easier to read, now using hex escapes instead of octal, |
| 58 | and using \t, \n and \r instead of \011, \012 and \015 (respectively): |
| 59 | |
| 60 | >>> "\texample \r\n" + chr(0) + chr(255) |
| 61 | '\texample \r\n\x00\xff' # in 2.1 |
| 62 | '\011example \015\012\000\377' # in 2.0 |
| 63 | |
Moshe Zadka | 6af0ce0 | 2001-01-29 06:41:00 +0000 | [diff] [blame] | 64 | - Functions are now compared and hashed by identity, not by value, since |
| 65 | the func_code attribute is writable. |
| 66 | |
Fred Drake | fb9d712 | 2001-02-01 20:00:40 +0000 | [diff] [blame] | 67 | - Weak references (PEP 205) have been added. This involves a few |
| 68 | changes in the core, an extension module (_weakref), and a Python |
| 69 | module (weakref). The weakref module is the public interface. It |
| 70 | includes support for "explicit" weak references, proxy objects, and |
| 71 | mappings with weakly held values. |
| 72 | |
Jeremy Hylton | 0072d5a | 2001-02-01 22:53:15 +0000 | [diff] [blame] | 73 | - A 'continue' statement can now appear in a try block within the body |
| 74 | of a loop. It is still not possible to use continue in a finally |
Tim Peters | 9ea17ac | 2001-02-02 05:57:15 +0000 | [diff] [blame] | 75 | clause. |
Jeremy Hylton | 0072d5a | 2001-02-01 22:53:15 +0000 | [diff] [blame] | 76 | |
Tim Peters | d7b5e88 | 2001-01-25 03:36:26 +0000 | [diff] [blame] | 77 | Standard library |
| 78 | |
Barry Warsaw | 30dbd14 | 2001-01-31 22:14:01 +0000 | [diff] [blame] | 79 | - mailbox.py now has a new class, PortableUnixMailbox which is |
| 80 | identical to UnixMailbox but uses a more portable scheme for |
| 81 | determining From_ separators. Also, the constructors for all the |
| 82 | classes in this module have a new optional `factory' argument, which |
| 83 | is a callable used when new message classes must be instantiated by |
| 84 | the next() method. |
| 85 | |
Tim Peters | d7b5e88 | 2001-01-25 03:36:26 +0000 | [diff] [blame] | 86 | - random.py is now self-contained, and offers all the functionality of |
| 87 | the now-deprecated whrandom.py. See the docs for details. random.py |
| 88 | also supports new functions getstate() and setstate(), for saving |
Tim Peters | d52269b | 2001-01-25 06:23:18 +0000 | [diff] [blame] | 89 | and restoring the internal state of the generator; and jumpahead(n), |
| 90 | for quickly forcing the internal state to be the same as if n calls to |
| 91 | random() had been made. The latter is particularly useful for multi- |
| 92 | threaded programs, creating one instance of the random.Random() class for |
| 93 | each thread, then using .jumpahead() to force each instance to use a |
| 94 | non-overlapping segment of the full period. |
Tim Peters | d7b5e88 | 2001-01-25 03:36:26 +0000 | [diff] [blame] | 95 | |
Tim Peters | 0de88fc | 2001-02-01 04:59:18 +0000 | [diff] [blame] | 96 | - random.py's seed() function is new. For bit-for-bit compatibility with |
| 97 | prior releases, use the whseed function instead. The new seed function |
| 98 | addresses two problems: (1) The old function couldn't produce more than |
| 99 | about 2**24 distinct internal states; the new one about 2**45 (the best |
| 100 | that can be done in the Wichmann-Hill generator). (2) The old function |
| 101 | sometimes produced identical internal states when passed distinct |
| 102 | integers, and there was no simple way to predict when that would happen; |
| 103 | the new one guarantees to produce distinct internal states for all |
| 104 | arguments in [0, 27814431486576L). |
| 105 | |
Jeremy Hylton | 4c4fda0 | 2001-02-02 03:29:24 +0000 | [diff] [blame] | 106 | - The socket module now supports raw packets on Linux. The socket |
| 107 | family is AF_PACKET. |
| 108 | |
Tim Peters | 9ea17ac | 2001-02-02 05:57:15 +0000 | [diff] [blame] | 109 | - test_capi.py is a start at running tests of the Python C API. The tests |
| 110 | are implemented by the new Modules/_testmodule.c. |
| 111 | |
Jeremy Hylton | d6b1cf9 | 2001-02-02 20:06:28 +0000 | [diff] [blame] | 112 | - A new extension module, _symtable, provides provisional access to the |
| 113 | internal symbol table used by the Python compiler. A higher-level |
| 114 | interface will be added on top of _symtable in a future release. |
| 115 | |
Tim Peters | ee826f8 | 2001-01-31 19:39:44 +0000 | [diff] [blame] | 116 | Windows changes |
| 117 | |
| 118 | - Build procedure: the zlib project is built in a different way that |
| 119 | ensures the zlib header files used can no longer get out of synch with |
Tim Peters | 9ea17ac | 2001-02-02 05:57:15 +0000 | [diff] [blame] | 120 | the zlib binary used. See PCbuild\readme.txt for details. Your old |
| 121 | zlib-related directories can be deleted; you'll need to download fresh |
| 122 | source for zlib and unpack it into a new directory. |
Tim Peters | ee826f8 | 2001-01-31 19:39:44 +0000 | [diff] [blame] | 123 | |
Tim Peters | 9ea17ac | 2001-02-02 05:57:15 +0000 | [diff] [blame] | 124 | - Build: New subproject _test for the benefit of test_capi.py (see above). |
| 125 | |
Tim Peters | b16c56f | 2001-02-02 21:24:51 +0000 | [diff] [blame] | 126 | - Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent |
| 127 | interface to some Python compiler internals). |
| 128 | |
| 129 | - Build: Subproject ucnhash is gone, since the code was folded into the |
Tim Peters | 9ea17ac | 2001-02-02 05:57:15 +0000 | [diff] [blame] | 130 | unicodedata subproject. |
Tim Peters | d7b5e88 | 2001-01-25 03:36:26 +0000 | [diff] [blame] | 131 | |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 132 | What's New in Python 2.1 alpha 1? |
| 133 | ================================= |
| 134 | |
| 135 | Core language, builtins, and interpreter |
| 136 | |
Marc-André Lemburg | ebb195b | 2001-01-20 10:34:52 +0000 | [diff] [blame] | 137 | - There is a new Unicode companion to the PyObject_Str() API |
| 138 | called PyObject_Unicode(). It behaves in the same way as the |
| 139 | former, but assures that the returned value is an Unicode object |
| 140 | (applying the usual coercion if necessary). |
Marc-André Lemburg | ad7c98e | 2001-01-17 17:09:53 +0000 | [diff] [blame] | 141 | |
Guido van Rossum | f98eda0 | 2001-01-17 15:54:45 +0000 | [diff] [blame] | 142 | - The comparison operators support "rich comparison overloading" (PEP |
| 143 | 207). C extension types can provide a rich comparison function in |
| 144 | the new tp_richcompare slot in the type object. The cmp() function |
| 145 | and the C function PyObject_Compare() first try the new rich |
| 146 | comparison operators before trying the old 3-way comparison. There |
| 147 | is also a new C API PyObject_RichCompare() (which also falls back on |
| 148 | the old 3-way comparison, but does not constrain the outcome of the |
| 149 | rich comparison to a Boolean result). |
| 150 | |
| 151 | The rich comparison function takes two objects (at least one of |
| 152 | which is guaranteed to have the type that provided the function) and |
| 153 | an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ, |
| 154 | Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python |
| 155 | object, which may be NotImplemented (in which case the tp_compare |
| 156 | slot function is used as a fallback, if defined). |
| 157 | |
| 158 | Classes can overload individual comparison operators by defining one |
| 159 | or more of the methods__lt__, __le__, __eq__, __ne__, __gt__, |
Guido van Rossum | a88479f | 2001-01-18 14:28:08 +0000 | [diff] [blame] | 160 | __ge__. There are no explicit "reflected argument" versions of |
| 161 | these; instead, __lt__ and __gt__ are each other's reflection, |
| 162 | likewise for__le__ and __ge__; __eq__ and __ne__ are their own |
| 163 | reflection (similar at the C level). No other implications are |
| 164 | made; in particular, Python does not assume that == is the Boolean |
| 165 | inverse of !=, or that < is the Boolean inverse of >=. This makes |
| 166 | it possible to define types with partial orderings. |
Guido van Rossum | f98eda0 | 2001-01-17 15:54:45 +0000 | [diff] [blame] | 167 | |
| 168 | Classes or types that want to implement (in)equality tests but not |
| 169 | the ordering operators (i.e. unordered types) should implement == |
| 170 | and !=, and raise an error for the ordering operators. |
| 171 | |
Guido van Rossum | a88479f | 2001-01-18 14:28:08 +0000 | [diff] [blame] | 172 | It is possible to define types whose rich comparison results are not |
Guido van Rossum | f98eda0 | 2001-01-17 15:54:45 +0000 | [diff] [blame] | 173 | Boolean; e.g. a matrix type might want to return a matrix of bits |
| 174 | for A < B, giving elementwise comparisons. Such types should ensure |
| 175 | that any interpretation of their value in a Boolean context raises |
| 176 | an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot |
| 177 | at the C level) to always raise an exception. |
| 178 | |
Guido van Rossum | a88479f | 2001-01-18 14:28:08 +0000 | [diff] [blame] | 179 | - Complex numbers use rich comparisons to define == and != but raise |
| 180 | an exception for <, <=, > and >=. Unfortunately, this also means |
| 181 | that cmp() of two complex numbers raises an exception when the two |
| 182 | numbers differ. Since it is not mathematically meaningful to compare |
| 183 | complex numbers except for equality, I hope that this doesn't break |
| 184 | too much code. |
| 185 | |
Tim Peters | 1449585 | 2001-02-18 08:28:33 +0000 | [diff] [blame^] | 186 | - The outcome of comparing non-numeric objects of differerent types is |
| 187 | not defined by the language, other than that it's arbitrary but |
| 188 | consistent (see the Reference Manual). An implementation detail changed |
| 189 | in 2.1a1 such that None now compares less than any other object. Code |
| 190 | relying on this new behavior (like code that relied on the previous |
| 191 | behavior) does so at its own risk. |
| 192 | |
Barry Warsaw | 573b541 | 2001-01-15 20:43:18 +0000 | [diff] [blame] | 193 | - Functions and methods now support getting and setting arbitrarily |
| 194 | named attributes (PEP 232). Functions have a new __dict__ |
| 195 | (a.k.a. func_dict) which hold the function attributes. Methods get |
| 196 | and set attributes on their underlying im_func. It is a TypeError |
| 197 | to set an attribute on a bound method. |
| 198 | |
Guido van Rossum | 051e335 | 2001-01-15 19:11:10 +0000 | [diff] [blame] | 199 | - The xrange() object implementation has been improved so that |
| 200 | xrange(sys.maxint) can be used on 64-bit platforms. There's still a |
| 201 | limitation that in this case len(xrange(sys.maxint)) can't be |
| 202 | calculated, but the common idiom "for i in xrange(sys.maxint)" will |
| 203 | work fine as long as the index i doesn't actually reach 2**31. |
| 204 | (Python uses regular ints for sequence and string indices; fixing |
| 205 | that is much more work.) |
| 206 | |
Guido van Rossum | 1cc8f83 | 2001-01-12 16:25:08 +0000 | [diff] [blame] | 207 | - Two changes to from...import: |
| 208 | |
Guido van Rossum | ba38123 | 2001-02-03 15:06:40 +0000 | [diff] [blame] | 209 | 1) "from M import X" now works even if (after loading module M) |
| 210 | sys.modules['M'] is not a real module; it's basically a getattr() |
| 211 | operation with AttributeError exceptions changed into ImportError. |
Guido van Rossum | 1cc8f83 | 2001-01-12 16:25:08 +0000 | [diff] [blame] | 212 | |
| 213 | 2) "from M import *" now looks for M.__all__ to decide which names to |
| 214 | import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but |
| 215 | filters out names starting with '_' as before. Whether or not |
| 216 | __all__ exists, there's no restriction on the type of M. |
| 217 | |
Guido van Rossum | f61f166 | 2001-01-10 20:13:55 +0000 | [diff] [blame] | 218 | - File objects have a new method, xreadlines(). This is the fastest |
| 219 | way to iterate over all lines in a file: |
| 220 | |
| 221 | for line in file.xreadlines(): |
| 222 | ...do something to line... |
| 223 | |
| 224 | See the xreadlines module (mentioned below) for how to do this for |
| 225 | other file-like objects. |
| 226 | |
| 227 | - Even if you don't use file.xreadlines(), you may expect a speedup on |
| 228 | line-by-line input. The file.readline() method has been optimized |
Tim Peters | f29b64d | 2001-01-15 06:33:19 +0000 | [diff] [blame] | 229 | quite a bit in platform-specific ways: on systems (like Linux) that |
| 230 | support flockfile(), getc_unlocked(), and funlockfile(), those are |
| 231 | used by default. On systems (like Windows) without getc_unlocked(), |
| 232 | a complicated (but still thread-safe) method using fgets() is used by |
| 233 | default. |
| 234 | |
Tim Peters | d52269b | 2001-01-25 06:23:18 +0000 | [diff] [blame] | 235 | You can force use of the fgets() method by #define'ing |
| 236 | USE_FGETS_IN_GETLINE at build time (it may be faster than |
Tim Peters | f29b64d | 2001-01-15 06:33:19 +0000 | [diff] [blame] | 237 | getc_unlocked()). |
| 238 | |
Tim Peters | d52269b | 2001-01-25 06:23:18 +0000 | [diff] [blame] | 239 | You can force fgets() not to be used by #define'ing |
| 240 | DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test |
Tim Peters | f29b64d | 2001-01-15 06:33:19 +0000 | [diff] [blame] | 241 | test_bufio.py fails -- and let us know if it does!). |
| 242 | |
| 243 | - In addition, the fileinput module, while still slower than the other |
| 244 | methods on most platforms, has been sped up too, by using |
| 245 | file.readlines(sizehint). |
Guido van Rossum | f61f166 | 2001-01-10 20:13:55 +0000 | [diff] [blame] | 246 | |
| 247 | - Support for run-time warnings has been added, including a new |
| 248 | command line option (-W) to specify the disposition of warnings. |
| 249 | See the description of the warnings module below. |
| 250 | |
| 251 | - Extensive changes have been made to the coercion code. This mostly |
| 252 | affects extension modules (which can now implement mixed-type |
| 253 | numerical operators without having to use coercion), but |
| 254 | occasionally, in boundary cases the coercion semantics have changed |
| 255 | subtly. Since this was a terrible gray area of the language, this |
Guido van Rossum | ae72d87 | 2001-01-11 15:00:14 +0000 | [diff] [blame] | 256 | is considered an improvement. Also note that __rcmp__ is no longer |
Guido van Rossum | f61f166 | 2001-01-10 20:13:55 +0000 | [diff] [blame] | 257 | supported -- instead of calling __rcmp__, __cmp__ is called with |
Guido van Rossum | a88479f | 2001-01-18 14:28:08 +0000 | [diff] [blame] | 258 | reflected arguments. |
Guido van Rossum | f61f166 | 2001-01-10 20:13:55 +0000 | [diff] [blame] | 259 | |
Guido van Rossum | f98eda0 | 2001-01-17 15:54:45 +0000 | [diff] [blame] | 260 | - In connection with the coercion changes, a new built-in singleton |
| 261 | object, NotImplemented is defined. This can be returned for |
| 262 | operations that wish to indicate they are not implemented for a |
| 263 | particular combination of arguments. From C, this is |
| 264 | Py_NotImplemented. |
| 265 | |
Martin v. Löwis | be4c0f5 | 2001-01-04 20:30:56 +0000 | [diff] [blame] | 266 | - The interpreter accepts now bytecode files on the command line even |
| 267 | if they do not have a .pyc or .pyo extension. On Linux, after executing |
| 268 | |
Martin v. Löwis | e214baa | 2001-02-04 22:37:56 +0000 | [diff] [blame] | 269 | import imp,sys,string |
| 270 | magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"") |
| 271 | reg = ':pyc:M::%s::%s:' % (magic, sys.executable) |
| 272 | open("/proc/sys/fs/binfmt_misc/register","wb").write(reg) |
Martin v. Löwis | be4c0f5 | 2001-01-04 20:30:56 +0000 | [diff] [blame] | 273 | |
| 274 | any byte code file can be used as an executable (i.e. as an argument |
| 275 | to execve(2)). |
| 276 | |
Tim Peters | 9940b80 | 2000-12-01 07:59:35 +0000 | [diff] [blame] | 277 | - %[xXo] formats of negative Python longs now produce a sign |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 278 | character. In 1.6 and earlier, they never produced a sign, |
| 279 | and raised an error if the value of the long was too large |
| 280 | to fit in a Python int. In 2.0, they produced a sign if and |
| 281 | only if too large to fit in an int. This was inconsistent |
| 282 | across platforms (because the size of an int varies across |
| 283 | platforms), and inconsistent with hex() and oct(). Example: |
| 284 | |
| 285 | >>> "%x" % -0x42L |
Tim Peters | 9940b80 | 2000-12-01 07:59:35 +0000 | [diff] [blame] | 286 | '-42' # in 2.1 |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 287 | 'ffffffbe' # in 2.0 and before, on 32-bit machines |
| 288 | >>> hex(-0x42L) |
| 289 | '-0x42L' # in all versions of Python |
| 290 | |
Tim Peters | 9940b80 | 2000-12-01 07:59:35 +0000 | [diff] [blame] | 291 | The behavior of %d formats for negative Python longs remains |
| 292 | the same as in 2.0 (although in 1.6 and before, they raised |
| 293 | an error if the long didn't fit in a Python int). |
| 294 | |
| 295 | %u formats don't make sense for Python longs, but are allowed |
| 296 | and treated the same as %d in 2.1. In 2.0, a negative long |
| 297 | formatted via %u produced a sign if and only if too large to |
| 298 | fit in an int. In 1.6 and earlier, a negative long formatted |
| 299 | via %u raised an error if it was too big to fit in an int. |
| 300 | |
Guido van Rossum | 3661d39 | 2000-12-12 22:10:31 +0000 | [diff] [blame] | 301 | - Dictionary objects have an odd new method, popitem(). This removes |
| 302 | an arbitrary item from the dictionary and returns it (in the form of |
| 303 | a (key, value) pair). This can be useful for algorithms that use a |
| 304 | dictionary as a bag of "to do" items and repeatedly need to pick one |
| 305 | item. Such algorithms normally end up running in quadratic time; |
| 306 | using popitem() they can usually be made to run in linear time. |
| 307 | |
Tim Peters | 36cdad1 | 2000-12-29 02:06:45 +0000 | [diff] [blame] | 308 | Standard library |
| 309 | |
Thomas Wouters | fe38525 | 2001-01-19 23:16:56 +0000 | [diff] [blame] | 310 | - In the time module, the time argument to the functions strftime, |
| 311 | localtime, gmtime, asctime and ctime is now optional, defaulting to |
| 312 | the current time (in the local timezone). |
| 313 | |
Guido van Rossum | da91f22 | 2001-01-15 16:36:08 +0000 | [diff] [blame] | 314 | - The ftplib module now defaults to passive mode, which is deemed a |
| 315 | more useful default given that clients are often inside firewalls |
| 316 | these days. Note that this could break if ftplib is used to connect |
| 317 | to a *server* that is inside a firewall, from outside; this is |
| 318 | expected to be a very rare situation. To fix that, you can call |
| 319 | ftp.set_pasv(0). |
| 320 | |
Martin v. Löwis | 10a2787 | 2001-01-13 09:54:41 +0000 | [diff] [blame] | 321 | - The module site now treats .pth files not only for path configuration, |
| 322 | but also supports extensions to the initialization code: Lines starting |
| 323 | with import are executed. |
| 324 | |
Guido van Rossum | f61f166 | 2001-01-10 20:13:55 +0000 | [diff] [blame] | 325 | - There's a new module, warnings, which implements a mechanism for |
| 326 | issuing and filtering warnings. There are some new built-in |
| 327 | exceptions that serve as warning categories, and a new command line |
| 328 | option, -W, to control warnings (e.g. -Wi ignores all warnings, -We |
| 329 | turns warnings into errors). warnings.warn(message[, category]) |
| 330 | issues a warning message; this can also be called from C as |
| 331 | PyErr_Warn(category, message). |
| 332 | |
| 333 | - A new module xreadlines was added. This exports a single factory |
| 334 | function, xreadlines(). The intention is that this code is the |
| 335 | absolutely fastest way to iterate over all lines in an open |
| 336 | file(-like) object: |
| 337 | |
| 338 | import xreadlines |
| 339 | for line in xreadlines.xreadlines(file): |
| 340 | ...do something to line... |
| 341 | |
| 342 | This is equivalent to the previous the speed record holder using |
| 343 | file.readlines(sizehint). Note that if file is a real file object |
| 344 | (as opposed to a file-like object), this is equivalent: |
| 345 | |
| 346 | for line in file.xreadlines(): |
| 347 | ...do something to line... |
| 348 | |
Tim Peters | 36cdad1 | 2000-12-29 02:06:45 +0000 | [diff] [blame] | 349 | - The bisect module has new functions bisect_left, insort_left, |
| 350 | bisect_right and insort_right. The old names bisect and insort |
| 351 | are now aliases for bisect_right and insort_right. XXX_right |
| 352 | and XXX_left methods differ in what happens when the new element |
| 353 | compares equal to one or more elements already in the list: the |
| 354 | XXX_left methods insert to the left, the XXX_right methods to the |
Tim Peters | 742bb6f | 2001-01-05 08:05:32 +0000 | [diff] [blame] | 355 | right. Code that doesn't care where equal elements end up should |
| 356 | continue to use the old, short names ("bisect" and "insort"). |
Tim Peters | 36cdad1 | 2000-12-29 02:06:45 +0000 | [diff] [blame] | 357 | |
Andrew M. Kuchling | f6f3a89 | 2001-01-13 14:53:34 +0000 | [diff] [blame] | 358 | - The new curses.panel module wraps the panel library that forms part |
| 359 | of SYSV curses and ncurses. Contributed by Thomas Gellekum. |
| 360 | |
Guido van Rossum | f61f166 | 2001-01-10 20:13:55 +0000 | [diff] [blame] | 361 | - The SocketServer module now sets the allow_reuse_address flag by |
| 362 | default in the TCPServer class. |
| 363 | |
| 364 | - A new function, sys._getframe(), returns the stack frame pointer of |
| 365 | the caller. This is intended only as a building block for |
| 366 | higher-level mechanisms such as string interpolation. |
| 367 | |
| 368 | Build issues |
| 369 | |
Guido van Rossum | 1e33bdc | 2001-01-23 03:17:00 +0000 | [diff] [blame] | 370 | - For Unix (and Unix-compatible) builds, configuration and building of |
| 371 | extension modules is now greatly automated. Rather than having to |
| 372 | edit the Modules/Setup file to indicate which modules should be |
| 373 | built and where their include files and libraries are, a |
| 374 | distutils-based setup.py script now takes care of building most |
| 375 | extension modules. All extension modules built this way are built |
| 376 | as shared libraries. Only a few modules that must be linked |
| 377 | statically are still listed in the Setup file; you won't need to |
| 378 | edit their configuration. |
| 379 | |
| 380 | - Python should now build out of the box on Cygwin. If it doesn't, |
| 381 | mail to Jason Tishler (jlt63 at users.sourceforge.net). |
Guido van Rossum | f61f166 | 2001-01-10 20:13:55 +0000 | [diff] [blame] | 382 | |
| 383 | - Python now always uses its own (renamed) implementation of getopt() |
| 384 | -- there's too much variation among C library getopt() |
| 385 | implementations. |
| 386 | |
| 387 | - C++ compilers are better supported; the CXX macro is always set to a |
| 388 | C++ compiler if one is found. |
Tim Peters | 36cdad1 | 2000-12-29 02:06:45 +0000 | [diff] [blame] | 389 | |
Tim Peters | d92dfe0 | 2000-12-12 01:18:41 +0000 | [diff] [blame] | 390 | Windows changes |
| 391 | |
| 392 | - select module: By default under Windows, a select() call |
| 393 | can specify no more than 64 sockets. Python now boosts |
| 394 | this Microsoft default to 512. If you need even more than |
| 395 | that, see the MS docs (you'll need to #define FD_SETSIZE |
| 396 | and recompile Python from source). |
| 397 | |
Guido van Rossum | f61f166 | 2001-01-10 20:13:55 +0000 | [diff] [blame] | 398 | - Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3 |
| 399 | subdirectory is no more! |
| 400 | |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 401 | |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 402 | What's New in Python 2.0? |
Fred Drake | 1a64050 | 2000-10-16 20:27:25 +0000 | [diff] [blame] | 403 | ========================= |
Guido van Rossum | 6100033 | 1997-08-15 04:39:58 +0000 | [diff] [blame] | 404 | |
Guido van Rossum | 8ed602b | 2000-09-01 22:34:33 +0000 | [diff] [blame] | 405 | Below is a list of all relevant changes since release 1.6. Older |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 406 | changes are in the file HISTORY. If you are making the jump directly |
| 407 | from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the |
| 408 | HISTORY file! Many important changes listed there. |
Guido van Rossum | 6100033 | 1997-08-15 04:39:58 +0000 | [diff] [blame] | 409 | |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 410 | Alternatively, a good overview of the changes between 1.5.2 and 2.0 is |
| 411 | the document "What's New in Python 2.0" by Kuchling and Moshe Zadka: |
| 412 | http://starship.python.net/crew/amk/python/writing/new-python/. |
Guido van Rossum | 1f83cce | 1997-10-06 21:04:35 +0000 | [diff] [blame] | 413 | |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 414 | --Guido van Rossum (home page: http://www.pythonlabs.com/~guido/) |
Guido van Rossum | 437cfe8 | 1999-04-08 20:17:57 +0000 | [diff] [blame] | 415 | |
| 416 | ====================================================================== |
| 417 | |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 418 | What's new in 2.0 (since release candidate 1)? |
| 419 | ============================================== |
| 420 | |
| 421 | Standard library |
| 422 | |
| 423 | - The copy_reg module was modified to clarify its intended use: to |
| 424 | register pickle support for extension types, not for classes. |
| 425 | pickle() will raise a TypeError if it is passed a class. |
| 426 | |
| 427 | - Fixed a bug in gettext's "normalize and expand" code that prevented |
| 428 | it from finding an existing .mo file. |
| 429 | |
| 430 | - Restored support for HTTP/0.9 servers in httplib. |
| 431 | |
Tim Peters | 989b7b9 | 2000-10-16 20:24:53 +0000 | [diff] [blame] | 432 | - The math module was changed to stop raising OverflowError in case of |
| 433 | underflow, and return 0 instead in underflow cases. Whether Python |
| 434 | used to raise OverflowError in case of underflow was platform- |
| 435 | dependent (it did when the platform math library set errno to ERANGE |
| 436 | on underflow). |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 437 | |
| 438 | - Fixed a bug in StringIO that occurred when the file position was not |
| 439 | at the end of the file and write() was called with enough data to |
| 440 | extend past the end of the file. |
| 441 | |
| 442 | - Fixed a bug that caused Tkinter error messages to get lost on |
| 443 | Windows. The bug was fixed by replacing direct use of |
| 444 | interp->result with Tcl_GetStringResult(interp). |
| 445 | |
| 446 | - Fixed bug in urllib2 that caused it to fail when it received an HTTP |
| 447 | redirect response. |
| 448 | |
| 449 | - Several changes were made to distutils: Some debugging code was |
| 450 | removed from util. Fixed the installer used when an external zip |
| 451 | program (like WinZip) is not found; the source code for this |
| 452 | installer is in Misc/distutils. check_lib() was modified to behave |
| 453 | more like AC_CHECK_LIB by add other_libraries() as a parameter. The |
| 454 | test for whether installed modules are on sys.path was changed to |
| 455 | use both normcase() and normpath(). |
| 456 | |
Jeremy Hylton | d867a2c | 2000-10-16 20:41:38 +0000 | [diff] [blame] | 457 | - Several minor bugs were fixed in the xml package (the minidom, |
| 458 | pulldom, expatreader, and saxutils modules). |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 459 | |
| 460 | - The regression test driver (regrtest.py) behavior when invoked with |
| 461 | -l changed: It now reports a count of objects that are recognized as |
| 462 | garbage but not freed by the garbage collector. |
| 463 | |
Tim Peters | 989b7b9 | 2000-10-16 20:24:53 +0000 | [diff] [blame] | 464 | - The regression test for the math module was changed to test |
| 465 | exceptional behavior when the test is run in verbose mode. Python |
| 466 | cannot yet guarantee consistent exception behavior across platforms, |
| 467 | so the exception part of test_math is run only in verbose mode, and |
| 468 | may fail on your platform. |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 469 | |
| 470 | Internals |
| 471 | |
| 472 | - PyOS_CheckStack() has been disabled on Win64, where it caused |
| 473 | test_sre to fail. |
| 474 | |
| 475 | Build issues |
| 476 | |
| 477 | - Changed compiler flags, so that gcc is always invoked with -Wall and |
| 478 | -Wstrict-prototypes. Users compiling Python with GCC should see |
| 479 | exactly one warning, except if they have passed configure the |
Tim Peters | 989b7b9 | 2000-10-16 20:24:53 +0000 | [diff] [blame] | 480 | --with-pydebug flag. The expected warning is for getopt() in |
Tim Peters | adfb94f | 2000-10-16 20:51:33 +0000 | [diff] [blame] | 481 | Modules/main.c. This warning will be fixed for Python 2.1. |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 482 | |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 483 | - Fixed configure to add -threads argument during linking on OSF1. |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 484 | |
| 485 | Tools and other miscellany |
| 486 | |
| 487 | - The compiler in Tools/compiler was updated to support the new |
| 488 | language features introduced in 2.0: extended print statement, list |
| 489 | comprehensions, and augmented assignments. The new compiler should |
| 490 | also be backwards compatible with Python 1.5.2; the compiler will |
| 491 | always generate code for the version of the interpreter it runs |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 492 | under. |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 493 | |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 494 | What's new in 2.0 release candidate 1 (since beta 2)? |
| 495 | ===================================================== |
| 496 | |
Jeremy Hylton | 6040aaa | 2000-10-09 21:27:22 +0000 | [diff] [blame] | 497 | What is release candidate 1? |
| 498 | |
| 499 | We believe that release candidate 1 will fix all known bugs that we |
| 500 | intend to fix for the 2.0 final release. This release should be a bit |
| 501 | more stable than the previous betas. We would like to see even more |
| 502 | widespread testing before the final release, so we are producing this |
| 503 | release candidate. The final release will be exactly the same unless |
| 504 | any show-stopping (or brown bag) bugs are found by testers of the |
| 505 | release candidate. |
| 506 | |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 507 | All the changes since the last beta release are bug fixes or changes |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 508 | to support building Python for specific platforms. |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 509 | |
| 510 | Core language, builtins, and interpreter |
| 511 | |
| 512 | - A bug that caused crashes when __coerce__ was used with augmented |
| 513 | assignment, e.g. +=, was fixed. |
| 514 | |
| 515 | - Raise ZeroDivisionError when raising zero to a negative number, |
| 516 | e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin |
| 517 | power operator and the result of math.pow(0.0, -2.0) will vary by |
| 518 | platform. On Linux, it raises a ValueError. |
| 519 | |
| 520 | - A bug in Unicode string interpolation was fixed that occasionally |
| 521 | caused errors with formats including "%%". For example, the |
| 522 | following expression "%% %s" % u"abc" no longer raises a TypeError. |
| 523 | |
| 524 | - Compilation of deeply nested expressions raises MemoryError instead |
| 525 | of SyntaxError, e.g. eval("[" * 50 + "]" * 50). |
| 526 | |
| 527 | - In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode, |
| 528 | rendering them useless. They are now written in binary mode again. |
| 529 | |
| 530 | Standard library |
| 531 | |
| 532 | - Keyword arguments are now accepted for most pattern and match object |
| 533 | methods in SRE, the standard regular expression engine. |
| 534 | |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 535 | - In SRE, fixed error with negative lookahead and lookbehind that |
Jeremy Hylton | 32e20ff | 2000-10-09 19:48:11 +0000 | [diff] [blame] | 536 | manifested itself as a runtime error in patterns like "(?<!abc)(def)". |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 537 | |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 538 | - Several bugs in the Unicode handling and error handling in _tkinter |
| 539 | were fixed. |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 540 | |
| 541 | - Fix memory management errors in Merge() and Tkapp_Call() routines. |
| 542 | |
| 543 | - Several changes were made to cStringIO to make it compatible with |
| 544 | the file-like object interface and with StringIO. If operations are |
| 545 | performed on a closed object, an exception is raised. The truncate |
| 546 | method now accepts a position argument and readline accepts a size |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 547 | argument. |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 548 | |
| 549 | - There were many changes made to the linuxaudiodev module and its |
| 550 | test suite; as a result, a short, unexpected audio sample should now |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 551 | play when the regression test is run. |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 552 | |
| 553 | Note that this module is named poorly, because it should work |
| 554 | correctly on any platform that supports the Open Sound System |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 555 | (OSS). |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 556 | |
| 557 | The module now raises exceptions when errors occur instead of |
| 558 | crashing. It also defines the AFMT_A_LAW format (logarithmic A-law |
| 559 | audio) and defines a getptr() method that calls the |
| 560 | SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide. |
| 561 | |
| 562 | - The library_version attribute, introduced in an earlier beta, was |
| 563 | removed because it can not be supported with early versions of the C |
| 564 | readline library, which provides no way to determine the version at |
| 565 | compile-time. |
| 566 | |
| 567 | - The binascii module is now enabled on Win64. |
| 568 | |
Tim Peters | 46446d6 | 2000-10-09 21:19:31 +0000 | [diff] [blame] | 569 | - tokenize.py no longer suffers "recursion depth" errors when parsing |
| 570 | programs with very long string literals. |
| 571 | |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 572 | Internals |
| 573 | |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 574 | - Fixed several buffer overflow vulnerabilities in calculate_path(), |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 575 | which is called when the interpreter starts up to determine where |
| 576 | the standard library is installed. These vulnerabilities affect all |
| 577 | previous versions of Python and can be exploited by setting very |
| 578 | long values for PYTHONHOME or argv[0]. The risk is greatest for a |
| 579 | setuid Python script, although use of the wrapper in |
| 580 | Misc/setuid-prog.c will eliminate the vulnerability. |
| 581 | |
| 582 | - Fixed garbage collection bugs in instance creation that were |
| 583 | triggered when errors occurred during initialization. The solution, |
| 584 | applied in cPickle and in PyInstance_New(), is to call |
| 585 | PyObject_GC_Init() after the initialization of the object's |
| 586 | container attributes is complete. |
| 587 | |
| 588 | - pyexpat adds definitions of PyModule_AddStringConstant and |
| 589 | PyModule_AddObject if the Python version is less than 2.0, which |
| 590 | provides compatibility with PyXML on Python 1.5.2. |
| 591 | |
| 592 | - If the platform has a bogus definition for LONG_BIT (the number of |
| 593 | bits in a long), an error will be reported at compile time. |
| 594 | |
| 595 | - Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage |
| 596 | collection crashes and possibly other, unreported crashes. |
| 597 | |
| 598 | - Fixed a memory leak in _PyUnicode_Fini(). |
| 599 | |
| 600 | Build issues |
| 601 | |
| 602 | - configure now accepts a --with-suffix option that specifies the |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 603 | executable suffix. This is useful for builds on Cygwin and Mac OS |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 604 | X, for example. |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 605 | |
| 606 | - The mmap.PAGESIZE constant is now initialized using sysconf when |
| 607 | possible, which eliminates a dependency on -lucb for Reliant UNIX. |
| 608 | |
| 609 | - The md5 file should now compile on all platforms. |
| 610 | |
| 611 | - The select module now compiles on platforms that do not define |
| 612 | POLLRDNORM and related constants. |
| 613 | |
| 614 | - Darwin (Mac OS X): Initial support for static builds on this |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 615 | platform. |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 616 | |
Jeremy Hylton | 1092120 | 2000-10-09 18:34:12 +0000 | [diff] [blame] | 617 | - BeOS: A number of changes were made to the build and installation |
| 618 | process. ar-fake now operates on a directory of object files. |
| 619 | dl_export.h is gone, and its macros now appear on the mwcc command |
| 620 | line during build on PPC BeOS. |
| 621 | |
Jeremy Hylton | d6e2023 | 2000-10-16 20:08:38 +0000 | [diff] [blame] | 622 | - Platform directory in lib/python2.0 is "plat-beos5" (or |
Jeremy Hylton | 1092120 | 2000-10-09 18:34:12 +0000 | [diff] [blame] | 623 | "plat-beos4", if building on BeOS 4.5), rather than "plat-beos". |
Jeremy Hylton | ed9e644 | 2000-10-09 18:26:42 +0000 | [diff] [blame] | 624 | |
| 625 | - Cygwin: Support for shared libraries, Tkinter, and sockets. |
| 626 | |
| 627 | - SunOS 4.1.4_JL: Fix test for directory existence in configure. |
| 628 | |
| 629 | Tools and other miscellany |
| 630 | |
| 631 | - Removed debugging prints from main used with freeze. |
| 632 | |
Tim Peters | 46446d6 | 2000-10-09 21:19:31 +0000 | [diff] [blame] | 633 | - IDLE auto-indent no longer crashes when it encounters Unicode |
| 634 | characters. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 635 | |
| 636 | What's new in 2.0 beta 2 (since beta 1)? |
| 637 | ======================================== |
| 638 | |
| 639 | Core language, builtins, and interpreter |
| 640 | |
Tim Peters | 482c021 | 2000-09-26 06:33:09 +0000 | [diff] [blame] | 641 | - Add support for unbounded ints in %d,i,u,x,X,o formats; for example |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 642 | "%d" % 2L**64 == "18446744073709551616". |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 643 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 644 | - Add -h and -V command line options to print the usage message and |
| 645 | Python version number and exit immediately. |
| 646 | |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 647 | - eval() and exec accept Unicode objects as code parameters. |
| 648 | |
| 649 | - getattr() and setattr() now also accept Unicode objects for the |
| 650 | attribute name, which are converted to strings using the default |
| 651 | encoding before lookup. |
| 652 | |
| 653 | - Multiplication on string and Unicode now does proper bounds |
| 654 | checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated |
| 655 | string is too long." |
| 656 | |
| 657 | - Better error message when continue is found in try statement in a |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 658 | loop. |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 659 | |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 660 | |
| 661 | Standard library and extensions |
| 662 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 663 | - array: reverse() method of array now works. buffer_info() now does |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 664 | argument checking; it still takes no arguments. |
| 665 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 666 | - asyncore/asynchat: Included most recent version from Sam Rushing. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 667 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 668 | - cgi: Accept '&' or ';' as separator characters when parsing form data. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 669 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 670 | - CGIHTTPServer: Now works on Windows (and perhaps even Mac). |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 671 | |
| 672 | - ConfigParser: When reading the file, options spelled in upper case |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 673 | letters are now correctly converted to lowercase. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 674 | |
| 675 | - copy: Copy Unicode objects atomically. |
| 676 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 677 | - cPickle: Fail gracefully when copy_reg can't be imported. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 678 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 679 | - cStringIO: Implemented readlines() method. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 680 | |
Fred Drake | 67233bc | 2000-09-26 16:40:27 +0000 | [diff] [blame] | 681 | - dbm: Add get() and setdefault() methods to dbm object. Add constant |
| 682 | `library' to module that names the library used. Added doc strings |
| 683 | and method names to error messages. Uses configure to determine |
| 684 | which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is |
| 685 | now available options. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 686 | |
| 687 | - distutils: Update to version 0.9.3. |
| 688 | |
| 689 | - dl: Add several dl.RTLD_ constants. |
| 690 | |
| 691 | - fpectl: Now supported on FreeBSD. |
| 692 | |
| 693 | - gc: Add DEBUG_SAVEALL option. When enabled all garbage objects |
| 694 | found by the collector will be saved in gc.garbage. This is useful |
| 695 | for debugging a program that creates reference cycles. |
| 696 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 697 | - httplib: Three changes: Restore support for set_debuglevel feature |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 698 | of HTTP class. Do not close socket on zero-length response. Do not |
| 699 | crash when server sends invalid content-length header. |
| 700 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 701 | - mailbox: Mailbox class conforms better to qmail specifications. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 702 | |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 703 | - marshal: When reading a short, sign-extend on platforms where shorts |
| 704 | are bigger than 16 bits. When reading a long, repair the unportable |
| 705 | sign extension that was being done for 64-bit machines. (It assumed |
| 706 | that signed right shift sign-extends.) |
| 707 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 708 | - operator: Add contains(), invert(), __invert__() as aliases for |
| 709 | __contains__(), inv(), and __inv__() respectively. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 710 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 711 | - os: Add support for popen2() and popen3() on all platforms where |
| 712 | fork() exists. (popen4() is still in the works.) |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 713 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 714 | - os: (Windows only:) Add startfile() function that acts like double- |
Tim Peters | 482c021 | 2000-09-26 06:33:09 +0000 | [diff] [blame] | 715 | clicking on a file in Explorer (or passing the file name to the |
| 716 | DOS "start" command). |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 717 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 718 | - os.path: (Windows, DOS:) Treat trailing colon correctly in |
Tim Peters | 482c021 | 2000-09-26 06:33:09 +0000 | [diff] [blame] | 719 | os.path.join. os.path.join("a:", "b") yields "a:b". |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 720 | |
| 721 | - pickle: Now raises ValueError when an invalid pickle that contains |
| 722 | a non-string repr where a string repr was expected. This behavior |
| 723 | matches cPickle. |
| 724 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 725 | - posixfile: Remove broken __del__() method. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 726 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 727 | - py_compile: support CR+LF line terminators in source file. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 728 | |
| 729 | - readline: Does not immediately exit when ^C is hit when readline and |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 730 | threads are configured. Adds definition of rl_library_version. (The |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 731 | latter addition requires GNU readline 2.2 or later.) |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 732 | |
| 733 | - rfc822: Domain literals returned by AddrlistClass method |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 734 | getdomainliteral() are now properly wrapped in brackets. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 735 | |
| 736 | - site: sys.setdefaultencoding() should only be called in case the |
Tim Peters | 482c021 | 2000-09-26 06:33:09 +0000 | [diff] [blame] | 737 | standard default encoding ("ascii") is changed. This saves quite a |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 738 | few cycles during startup since the first call to |
| 739 | setdefaultencoding() will initialize the codec registry and the |
| 740 | encodings package. |
| 741 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 742 | - socket: Support for size hint in readlines() method of object returned |
| 743 | by makefile(). |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 744 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 745 | - sre: Added experimental expand() method to match objects. Does not |
Jeremy Hylton | 625915e | 2000-10-02 13:43:33 +0000 | [diff] [blame] | 746 | use buffer interface on Unicode strings. Does not hang if group id |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 747 | is followed by whitespace. |
| 748 | |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 749 | - StringIO: Size hint in readlines() is now supported as documented. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 750 | |
| 751 | - struct: Check ranges for bytes and shorts. |
| 752 | |
| 753 | - urllib: Improved handling of win32 proxy settings. Fixed quote and |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 754 | quote_plus functions so that the always encode a comma. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 755 | |
| 756 | - Tkinter: Image objects are now guaranteed to have unique ids. Set |
| 757 | event.delta to zero if Tk version doesn't support mousewheel. |
| 758 | Removed some debugging prints. |
| 759 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 760 | - UserList: now implements __contains__(). |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 761 | |
Fred Drake | 67233bc | 2000-09-26 16:40:27 +0000 | [diff] [blame] | 762 | - webbrowser: On Windows, use os.startfile() instead of os.popen(), |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 763 | which works around a bug in Norton AntiVirus 2000 that leads directly |
| 764 | to a Blue Screen freeze. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 765 | |
| 766 | - xml: New version detection code allows PyXML to override standard |
| 767 | XML package if PyXML version is greater than 0.6.1. |
| 768 | |
Fred Drake | 64bb380 | 2000-09-26 16:21:35 +0000 | [diff] [blame] | 769 | - xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom |
| 770 | (conventional DOM), and xml.dom.pulldom, which allows building the DOM |
| 771 | tree only for nodes which are sufficiently interesting to a specific |
| 772 | application. Does not provide the HTML-specific extensions. Still |
| 773 | undocumented. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 774 | |
Fred Drake | 64bb380 | 2000-09-26 16:21:35 +0000 | [diff] [blame] | 775 | - xml.sax: SAX 2 support for Python, including all the handler |
| 776 | interfaces needed to process XML 1.0 compliant XML. Some |
| 777 | documentation is already available. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 778 | |
Fred Drake | 64bb380 | 2000-09-26 16:21:35 +0000 | [diff] [blame] | 779 | - pyexpat: Renamed to xml.parsers.expat since this is part of the new, |
| 780 | packagized XML support. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 781 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 782 | |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 783 | C API |
| 784 | |
| 785 | - Add three new convenience functions for module initialization -- |
| 786 | PyModule_AddObject(), PyModule_AddIntConstant(), and |
| 787 | PyModule_AddStringConstant(). |
| 788 | |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 789 | - Cleaned up definition of NULL in C source code; all definitions were |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 790 | removed and add #error to Python.h if NULL isn't defined after |
| 791 | #include of stdio.h. |
| 792 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 793 | - Py_PROTO() macros that were removed in 2.0b1 have been restored for |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 794 | backwards compatibility (at the source level) with old extensions. |
| 795 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 796 | - A wrapper API was added for signal() and sigaction(). Instead of |
| 797 | either function, always use PyOS_getsig() to get a signal handler |
| 798 | and PyOS_setsig() to set one. A new convenience typedef |
| 799 | PyOS_sighandler_t is defined for the type of signal handlers. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 800 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 801 | - Add PyString_AsStringAndSize() function that provides access to the |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 802 | internal data buffer and size of a string object -- or the default |
| 803 | encoded version of a Unicode object. |
| 804 | |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 805 | - PyString_Size() and PyString_AsString() accept Unicode objects. |
| 806 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 807 | - The standard header <limits.h> is now included by Python.h (if it |
Fred Drake | 64bb380 | 2000-09-26 16:21:35 +0000 | [diff] [blame] | 808 | exists). INT_MAX and LONG_MAX will always be defined, even if |
| 809 | <limits.h> is not available. |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 810 | |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 811 | - PyFloat_FromString takes a second argument, pend, that was |
| 812 | effectively useless. It is now officially useless but preserved for |
| 813 | backwards compatibility. If the pend argument is not NULL, *pend is |
| 814 | set to NULL. |
| 815 | |
| 816 | - PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects |
| 817 | for the attribute name. See note on getattr() above. |
| 818 | |
| 819 | - A few bug fixes to argument processing for Unicode. |
| 820 | PyArg_ParseTupleAndKeywords() now accepts "es#" and "es". |
| 821 | PyArg_Parse() special cases "s#" for Unicode objects; it returns a |
| 822 | pointer to the default encoded string data instead of to the raw |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 823 | UTF-16. |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 824 | |
| 825 | - Py_BuildValue accepts B format (for bgen-generated code). |
| 826 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 827 | |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 828 | Internals |
| 829 | |
| 830 | - On Unix, fix code for finding Python installation directory so that |
| 831 | it works when argv[0] is a relative path. |
| 832 | |
Andrew M. Kuchling | a1099be | 2000-12-15 01:16:43 +0000 | [diff] [blame] | 833 | - Added a true unicode_internal_encode() function and fixed the |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 834 | unicode_internal_decode function() to support Unicode objects directly |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 835 | rather than by generating a copy of the object. |
| 836 | |
Tim Peters | 482c021 | 2000-09-26 06:33:09 +0000 | [diff] [blame] | 837 | - Several of the internal Unicode tables are much smaller now, and |
| 838 | the source code should be much friendlier to weaker compilers. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 839 | |
Jeremy Hylton | 97693b0 | 2000-09-26 17:42:51 +0000 | [diff] [blame] | 840 | - In the garbage collector: Fixed bug in collection of tuples. Fixed |
| 841 | bug that caused some instances to be removed from the container set |
| 842 | while they were still live. Fixed parsing in gc.set_debug() for |
| 843 | platforms where sizeof(long) > sizeof(int). |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 844 | |
| 845 | - Fixed refcount problem in instance deallocation that only occurred |
| 846 | when Py_REF_DEBUG was defined and Py_TRACE_REFS was not. |
| 847 | |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 848 | - On Windows, getpythonregpath is now protected against null data in |
| 849 | registry key. |
| 850 | |
| 851 | - On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 852 | condition. |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 853 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 854 | |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 855 | Build and platform-specific issues |
| 856 | |
| 857 | - Better support of GNU Pth via --with-pth configure option. |
| 858 | |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 859 | - Python/C API now properly exposed to dynamically-loaded extension |
| 860 | modules on Reliant UNIX. |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 861 | |
| 862 | - Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c: |
| 863 | Don't define MS_SYNC to be zero when it is undefined. Added missing |
| 864 | prototypes in posixmodule.c. |
| 865 | |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 866 | - Improved support for HP-UX build. Threads should now be correctly |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 867 | configured (on HP-UX 10.20 and 11.00). |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 868 | |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 869 | - Fix largefile support on older NetBSD systems and OpenBSD by adding |
| 870 | define for TELL64. |
| 871 | |
| 872 | |
| 873 | Tools and other miscellany |
| 874 | |
| 875 | - ftpmirror: Call to main() is wrapped in if __name__ == "__main__". |
| 876 | |
| 877 | - freeze: The modulefinder now works with 2.0 opcodes. |
| 878 | |
Tim Peters | a3a3a03 | 2000-11-30 05:22:44 +0000 | [diff] [blame] | 879 | - IDLE: |
Jeremy Hylton | fa2e2c1 | 2000-09-26 16:31:30 +0000 | [diff] [blame] | 880 | Move hackery of sys.argv until after the Tk instance has been |
| 881 | created, which allows the application-specific Tkinter |
| 882 | initialization to be executed if present; also pass an explicit |
| 883 | className parameter to the Tk() constructor. |
Fred Drake | 64bb380 | 2000-09-26 16:21:35 +0000 | [diff] [blame] | 884 | |
Jeremy Hylton | 1b61859 | 2000-09-26 05:32:36 +0000 | [diff] [blame] | 885 | |
| 886 | What's new in 2.0 beta 1? |
| 887 | ========================= |
| 888 | |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 889 | Source Incompatibilities |
| 890 | ------------------------ |
| 891 | |
| 892 | None. Note that 1.6 introduced several incompatibilities with 1.5.2, |
| 893 | such as single-argument append(), connect() and bind(), and changes to |
| 894 | str(long) and repr(float). |
| 895 | |
| 896 | |
| 897 | Binary Incompatibilities |
| 898 | ------------------------ |
| 899 | |
| 900 | - Third party extensions built for Python 1.5.x or 1.6 cannot be used |
| 901 | with Python 2.0; these extensions will have to be rebuilt for Python |
| 902 | 2.0. |
| 903 | |
| 904 | - On Windows, attempting to import a third party extension built for |
| 905 | Python 1.5.x or 1.6 results in an immediate crash; there's not much we |
| 906 | can do about this. Check your PYTHONPATH environment variable! |
| 907 | |
| 908 | - Python bytecode files (*.pyc and *.pyo) are not compatible between |
| 909 | releases. |
| 910 | |
| 911 | |
| 912 | Overview of Changes Since 1.6 |
| 913 | ----------------------------- |
| 914 | |
| 915 | There are many new modules (including brand new XML support through |
| 916 | the xml package, and i18n support through the gettext module); a list |
| 917 | of all new modules is included below. Lots of bugs have been fixed. |
| 918 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 919 | The process for making major new changes to the language has changed |
| 920 | since Python 1.6. Enhancements must now be documented by a Python |
| 921 | Enhancement Proposal (PEP) before they can be accepted. |
| 922 | |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 923 | There are several important syntax enhancements, described in more |
| 924 | detail below: |
| 925 | |
| 926 | - Augmented assignment, e.g. x += 1 |
| 927 | |
| 928 | - List comprehensions, e.g. [x**2 for x in range(10)] |
| 929 | |
| 930 | - Extended import statement, e.g. import Module as Name |
| 931 | |
| 932 | - Extended print statement, e.g. print >> file, "Hello" |
| 933 | |
| 934 | Other important changes: |
| 935 | |
| 936 | - Optional collection of cyclical garbage |
| 937 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 938 | Python Enhancement Proposal (PEP) |
| 939 | --------------------------------- |
| 940 | |
| 941 | PEP stands for Python Enhancement Proposal. A PEP is a design |
| 942 | document providing information to the Python community, or describing |
| 943 | a new feature for Python. The PEP should provide a concise technical |
| 944 | specification of the feature and a rationale for the feature. |
| 945 | |
| 946 | We intend PEPs to be the primary mechanisms for proposing new |
| 947 | features, for collecting community input on an issue, and for |
| 948 | documenting the design decisions that have gone into Python. The PEP |
| 949 | author is responsible for building consensus within the community and |
| 950 | documenting dissenting opinions. |
| 951 | |
| 952 | The PEPs are available at http://python.sourceforge.net/peps/. |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 953 | |
| 954 | Augmented Assignment |
| 955 | -------------------- |
| 956 | |
| 957 | This must have been the most-requested feature of the past years! |
| 958 | Eleven new assignment operators were added: |
| 959 | |
Guido van Rossum | e905e95 | 2000-09-05 12:42:46 +0000 | [diff] [blame] | 960 | += -= *= /= %= **= <<= >>= &= ^= |= |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 961 | |
| 962 | For example, |
| 963 | |
| 964 | A += B |
| 965 | |
| 966 | is similar to |
| 967 | |
| 968 | A = A + B |
| 969 | |
| 970 | except that A is evaluated only once (relevant when A is something |
| 971 | like dict[index].attr). |
| 972 | |
| 973 | However, if A is a mutable object, A may be modified in place. Thus, |
| 974 | if A is a number or a string, A += B has the same effect as A = A+B |
| 975 | (except A is only evaluated once); but if a is a list, A += B has the |
| 976 | same effect as A.extend(B)! |
| 977 | |
| 978 | Classes and built-in object types can override the new operators in |
| 979 | order to implement the in-place behavior; the not-in-place behavior is |
| 980 | used automatically as a fallback when an object doesn't implement the |
| 981 | in-place behavior. For classes, the method name is derived from the |
| 982 | method name for the corresponding not-in-place operator by inserting |
| 983 | an 'i' in front of the name, e.g. __iadd__ implements in-place |
| 984 | __add__. |
| 985 | |
| 986 | Augmented assignment was implemented by Thomas Wouters. |
| 987 | |
| 988 | |
| 989 | List Comprehensions |
| 990 | ------------------- |
| 991 | |
| 992 | This is a flexible new notation for lists whose elements are computed |
| 993 | from another list (or lists). The simplest form is: |
| 994 | |
| 995 | [<expression> for <variable> in <sequence>] |
| 996 | |
Guido van Rossum | 56db095 | 2000-09-06 23:34:25 +0000 | [diff] [blame] | 997 | For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9]. |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 998 | This is more efficient than a for loop with a list.append() call. |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 999 | |
| 1000 | You can also add a condition: |
| 1001 | |
| 1002 | [<expression> for <variable> in <sequence> if <condition>] |
| 1003 | |
| 1004 | For example, [w for w in words if w == w.lower()] would yield the list |
| 1005 | of words that contain no uppercase characters. This is more efficient |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 1006 | than a for loop with an if statement and a list.append() call. |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1007 | |
| 1008 | You can also have nested for loops and more than one 'if' clause. For |
| 1009 | example, here's a function that flattens a sequence of sequences:: |
| 1010 | |
| 1011 | def flatten(seq): |
| 1012 | return [x for subseq in seq for x in subseq] |
| 1013 | |
| 1014 | flatten([[0], [1,2,3], [4,5], [6,7,8,9], []]) |
| 1015 | |
| 1016 | This prints |
| 1017 | |
| 1018 | [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] |
| 1019 | |
| 1020 | List comprehensions originated as a patch set from Greg Ewing; Skip |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1021 | Montanaro and Thomas Wouters also contributed. Described by PEP 202. |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1022 | |
| 1023 | |
| 1024 | Extended Import Statement |
| 1025 | ------------------------- |
| 1026 | |
| 1027 | Many people have asked for a way to import a module under a different |
| 1028 | name. This can be accomplished like this: |
| 1029 | |
| 1030 | import foo |
| 1031 | bar = foo |
| 1032 | del foo |
| 1033 | |
| 1034 | but this common idiom gets old quickly. A simple extension of the |
| 1035 | import statement now allows this to be written as follows: |
| 1036 | |
| 1037 | import foo as bar |
| 1038 | |
| 1039 | There's also a variant for 'from ... import': |
| 1040 | |
| 1041 | from foo import bar as spam |
| 1042 | |
| 1043 | This also works with packages; e.g. you can write this: |
| 1044 | |
| 1045 | import test.regrtest as regrtest |
| 1046 | |
| 1047 | Note that 'as' is not a new keyword -- it is recognized only in this |
| 1048 | context (this is only possible because the syntax for the import |
| 1049 | statement doesn't involve expressions). |
| 1050 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1051 | Implemented by Thomas Wouters. Described by PEP 221. |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1052 | |
| 1053 | |
| 1054 | Extended Print Statement |
| 1055 | ------------------------ |
| 1056 | |
| 1057 | Easily the most controversial new feature, this extension to the print |
| 1058 | statement adds an option to make the output go to a different file |
| 1059 | than the default sys.stdout. |
| 1060 | |
| 1061 | For example, to write an error message to sys.stderr, you can now |
| 1062 | write: |
| 1063 | |
| 1064 | print >> sys.stderr, "Error: bad dog!" |
| 1065 | |
| 1066 | As a special feature, if the expression used to indicate the file |
Fred Drake | 45888ff | 2000-09-29 17:09:11 +0000 | [diff] [blame] | 1067 | evaluates to None, the current value of sys.stdout is used. Thus: |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1068 | |
| 1069 | print >> None, "Hello world" |
| 1070 | |
| 1071 | is equivalent to |
| 1072 | |
| 1073 | print "Hello world" |
| 1074 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1075 | Design and implementation by Barry Warsaw. Described by PEP 214. |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1076 | |
| 1077 | |
| 1078 | Optional Collection of Cyclical Garbage |
| 1079 | --------------------------------------- |
| 1080 | |
| 1081 | Python is now equipped with a garbage collector that can hunt down |
| 1082 | cyclical references between Python objects. It's no replacement for |
| 1083 | reference counting; in fact, it depends on the reference counts being |
| 1084 | correct, and decides that a set of objects belong to a cycle if all |
| 1085 | their reference counts can be accounted for from their references to |
| 1086 | each other. This devious scheme was first proposed by Eric Tiedemann, |
| 1087 | and brought to implementation by Neil Schemenauer. |
| 1088 | |
| 1089 | There's a module "gc" that lets you control some parameters of the |
| 1090 | garbage collection. There's also an option to the configure script |
| 1091 | that lets you enable or disable the garbage collection. In 2.0b1, |
| 1092 | it's on by default, so that we (hopefully) can collect decent user |
| 1093 | experience with this new feature. There are some questions about its |
Fred Drake | 9f11cf8 | 2000-09-29 17:54:40 +0000 | [diff] [blame] | 1094 | performance. If it proves to be too much of a problem, we'll turn it |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1095 | off by default in the final 2.0 release. |
| 1096 | |
| 1097 | |
| 1098 | Smaller Changes |
| 1099 | --------------- |
| 1100 | |
| 1101 | A new function zip() was added. zip(seq1, seq2, ...) is equivalent to |
| 1102 | map(None, seq1, seq2, ...) when the sequences have the same length; |
| 1103 | i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When |
| 1104 | the lists are not all the same length, the shortest list wins: |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1105 | zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201. |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1106 | |
| 1107 | sys.version_info is a tuple (major, minor, micro, level, serial). |
| 1108 | |
| 1109 | Dictionaries have an odd new method, setdefault(key, default). |
| 1110 | dict.setdefault(key, default) returns dict[key] if it exists; if not, |
| 1111 | it sets dict[key] to default and returns that value. Thus: |
| 1112 | |
| 1113 | dict.setdefault(key, []).append(item) |
| 1114 | |
| 1115 | does the same work as this common idiom: |
| 1116 | |
| 1117 | if not dict.has_key(key): |
| 1118 | dict[key] = [] |
| 1119 | dict[key].append(item) |
| 1120 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1121 | There are two new variants of SyntaxError that are raised for |
| 1122 | indentation-related errors: IndentationError and TabError. |
| 1123 | |
| 1124 | Changed \x to consume exactly two hex digits; see PEP 223. Added \U |
| 1125 | escape that consumes exactly eight hex digits. |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1126 | |
| 1127 | The limits on the size of expressions and file in Python source code |
| 1128 | have been raised from 2**16 to 2**32. Previous versions of Python |
| 1129 | were limited because the maximum argument size the Python VM accepted |
| 1130 | was 2**16. This limited the size of object constructor expressions, |
| 1131 | e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This |
| 1132 | limit was raised thanks to a patch by Charles Waldman that effectively |
| 1133 | fixes the problem. It is now much more likely that you will be |
| 1134 | limited by available memory than by an arbitrary limit in Python. |
| 1135 | |
| 1136 | The interpreter's maximum recursion depth can be modified by Python |
| 1137 | programs using sys.getrecursionlimit and sys.setrecursionlimit. This |
| 1138 | limit is the maximum number of recursive calls that can be made by |
| 1139 | Python code. The limit exists to prevent infinite recursion from |
| 1140 | overflowing the C stack and causing a core dump. The default value is |
| 1141 | 1000. The maximum safe value for a particular platform can be found |
| 1142 | by running Misc/find_recursionlimit.py. |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1143 | |
| 1144 | New Modules and Packages |
| 1145 | ------------------------ |
| 1146 | |
| 1147 | atexit - for registering functions to be called when Python exits. |
| 1148 | |
| 1149 | imputil - Greg Stein's alternative API for writing custom import |
| 1150 | hooks. |
| 1151 | |
| 1152 | pyexpat - an interface to the Expat XML parser, contributed by Paul |
| 1153 | Prescod. |
| 1154 | |
| 1155 | xml - a new package with XML support code organized (so far) in three |
| 1156 | subpackages: xml.dom, xml.sax, and xml.parsers. Describing these |
| 1157 | would fill a volume. There's a special feature whereby a |
| 1158 | user-installed package named _xmlplus overrides the standard |
| 1159 | xmlpackage; this is intended to give the XML SIG a hook to distribute |
| 1160 | backwards-compatible updates to the standard xml package. |
| 1161 | |
| 1162 | webbrowser - a platform-independent API to launch a web browser. |
| 1163 | |
| 1164 | |
Guido van Rossum | e905e95 | 2000-09-05 12:42:46 +0000 | [diff] [blame] | 1165 | Changed Modules |
| 1166 | --------------- |
| 1167 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1168 | array -- new methods for array objects: count, extend, index, pop, and |
| 1169 | remove |
| 1170 | |
| 1171 | binascii -- new functions b2a_hex and a2b_hex that convert between |
| 1172 | binary data and its hex representation |
| 1173 | |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1174 | calendar -- Many new functions that support features including control |
| 1175 | over which day of the week is the first day, returning strings instead |
| 1176 | of printing them. Also new symbolic constants for days of week, |
| 1177 | e.g. MONDAY, ..., SUNDAY. |
| 1178 | |
| 1179 | cgi -- FieldStorage objects have a getvalue method that works like a |
| 1180 | dictionary's get method and returns the value attribute of the object. |
| 1181 | |
| 1182 | ConfigParser -- The parser object has new methods has_option, |
| 1183 | remove_section, remove_option, set, and write. They allow the module |
| 1184 | to be used for writing config files as well as reading them. |
| 1185 | |
| 1186 | ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now |
Guido van Rossum | e905e95 | 2000-09-05 12:42:46 +0000 | [diff] [blame] | 1187 | optionally support the RFC 959 REST command. |
| 1188 | |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1189 | gzip -- readline and readlines now accept optional size arguments |
Guido van Rossum | e905e95 | 2000-09-05 12:42:46 +0000 | [diff] [blame] | 1190 | |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1191 | httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See |
| 1192 | the module doc strings for details. |
Guido van Rossum | 830ca2a | 2000-09-05 15:34:16 +0000 | [diff] [blame] | 1193 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1194 | locale -- implement getdefaultlocale for Win32 and Macintosh |
| 1195 | |
| 1196 | marshal -- no longer dumps core when marshaling deeply nested or |
| 1197 | recursive data structures |
| 1198 | |
| 1199 | os -- new functions isatty, seteuid, setegid, setreuid, setregid |
| 1200 | |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1201 | os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3 |
| 1202 | support under Unix. |
| 1203 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1204 | os/pty -- support for openpty and forkpty |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1205 | |
| 1206 | os.path -- fix semantics of os.path.commonprefix |
| 1207 | |
| 1208 | smtplib -- support for sending very long messages |
| 1209 | |
| 1210 | socket -- new function getfqdn() |
| 1211 | |
| 1212 | readline -- new functions to read, write and truncate history files. |
| 1213 | The readline section of the library reference manual contains an |
| 1214 | example. |
| 1215 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1216 | select -- add interface to poll system call |
| 1217 | |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1218 | shutil -- new copyfileobj function |
| 1219 | |
| 1220 | SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the |
| 1221 | HTTP server. |
| 1222 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1223 | Tkinter -- optimization of function flatten |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1224 | |
| 1225 | urllib -- scans environment variables for proxy configuration, |
Tim Peters | 8b09233 | 2000-09-05 20:15:25 +0000 | [diff] [blame] | 1226 | e.g. http_proxy. |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1227 | |
| 1228 | whichdb -- recognizes dumbdbm format |
Guido van Rossum | e905e95 | 2000-09-05 12:42:46 +0000 | [diff] [blame] | 1229 | |
| 1230 | |
| 1231 | Obsolete Modules |
| 1232 | ---------------- |
| 1233 | |
| 1234 | None. However note that 1.6 made a whole slew of modules obsolete: |
| 1235 | stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail, |
| 1236 | poly, zmod, strop, util, whatsound. |
| 1237 | |
| 1238 | |
| 1239 | Changed, New, Obsolete Tools |
| 1240 | ---------------------------- |
| 1241 | |
Tim Peters | 8b09233 | 2000-09-05 20:15:25 +0000 | [diff] [blame] | 1242 | None. |
Guido van Rossum | e905e95 | 2000-09-05 12:42:46 +0000 | [diff] [blame] | 1243 | |
| 1244 | |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1245 | C-level Changes |
| 1246 | --------------- |
| 1247 | |
| 1248 | Several cleanup jobs were carried out throughout the source code. |
| 1249 | |
| 1250 | All C code was converted to ANSI C; we got rid of all uses of the |
| 1251 | Py_PROTO() macro, which makes the header files a lot more readable. |
| 1252 | |
| 1253 | Most of the portability hacks were moved to a new header file, |
| 1254 | pyport.h; several other new header files were added and some old |
| 1255 | header files were removed, in an attempt to create a more rational set |
| 1256 | of header files. (Few of these ever need to be included explicitly; |
| 1257 | they are all included by Python.h.) |
| 1258 | |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1259 | Trent Mick ensured portability to 64-bit platforms, under both Linux |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1260 | and Win64, especially for the new Intel Itanium processor. Mick also |
| 1261 | added large file support for Linux64 and Win64. |
Guido van Rossum | f2ffce0 | 2000-09-05 04:38:34 +0000 | [diff] [blame] | 1262 | |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1263 | The C APIs to return an object's size have been update to consistently |
| 1264 | use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In |
| 1265 | previous versions, the abstract interfaces used PyXXX_Length and the |
| 1266 | concrete interfaces used PyXXX_Size. The old names, |
| 1267 | e.g. PyObject_Length, are still available for backwards compatibility |
| 1268 | at the API level, but are deprecated. |
| 1269 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1270 | The PyOS_CheckStack function has been implemented on Windows by |
| 1271 | Fredrik Lundh. It prevents Python from failing with a stack overflow |
| 1272 | on Windows. |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1273 | |
| 1274 | The GC changes resulted in creation of two new slots on object, |
| 1275 | tp_traverse and tp_clear. The augmented assignment changes result in |
Guido van Rossum | 4338a28 | 2000-09-06 13:02:08 +0000 | [diff] [blame] | 1276 | the creation of a new slot for each in-place operator. |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1277 | |
| 1278 | The GC API creates new requirements for container types implemented in |
Guido van Rossum | 4338a28 | 2000-09-06 13:02:08 +0000 | [diff] [blame] | 1279 | C extension modules. See Include/objimpl.h for details. |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1280 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1281 | PyErr_Format has been updated to automatically calculate the size of |
| 1282 | the buffer needed to hold the formatted result string. This change |
| 1283 | prevents crashes caused by programmer error. |
Jeremy Hylton | bdebd54 | 2000-09-05 18:28:54 +0000 | [diff] [blame] | 1284 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1285 | New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable. |
Guido van Rossum | e905e95 | 2000-09-05 12:42:46 +0000 | [diff] [blame] | 1286 | |
Jeremy Hylton | 24c3d60 | 2000-09-05 19:36:26 +0000 | [diff] [blame] | 1287 | PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions |
| 1288 | that are the same as their non-Ex counterparts except they take an |
| 1289 | extra flag argument that tells them to close the file when done. |
| 1290 | |
| 1291 | XXX There were other API changes that should be fleshed out here. |
Guido van Rossum | ab9d6f0 | 1998-08-10 22:01:13 +0000 | [diff] [blame] | 1292 | |
Tim Peters | 8b09233 | 2000-09-05 20:15:25 +0000 | [diff] [blame] | 1293 | |
| 1294 | Windows Changes |
| 1295 | --------------- |
| 1296 | |
| 1297 | New popen2/popen3/peopen4 in os module (see Changed Modules above). |
| 1298 | |
| 1299 | os.popen is much more usable on Windows 95 and 98. See Microsoft |
| 1300 | Knowledge Base article Q150956. The Win9x workaround described there |
| 1301 | is implemented by the new w9xpopen.exe helper in the root of your |
| 1302 | Python installation. Note that Python uses this internally; it is not |
| 1303 | a standalone program. |
| 1304 | |
| 1305 | Administrator privileges are no longer required to install Python |
| 1306 | on Windows NT or Windows 2000. If you have administrator privileges, |
| 1307 | Python's registry info will be written under HKEY_LOCAL_MACHINE. |
| 1308 | Otherwise the installer backs off to writing Python's registry info |
Guido van Rossum | 4338a28 | 2000-09-06 13:02:08 +0000 | [diff] [blame] | 1309 | under HKEY_CURRENT_USER. The latter is sufficient for all "normal" |
Tim Peters | 8b09233 | 2000-09-05 20:15:25 +0000 | [diff] [blame] | 1310 | uses of Python, but will prevent some advanced uses from working |
| 1311 | (for example, running a Python script as an NT service, or possibly |
| 1312 | from CGI). |
| 1313 | |
| 1314 | [This was new in 1.6] The installer no longer runs a separate Tcl/Tk |
| 1315 | installer; instead, it installs the needed Tcl/Tk files directly in the |
| 1316 | Python directory. If you already have a Tcl/Tk installation, this |
| 1317 | wastes some disk space (about 4 Megs) but avoids problems with |
| 1318 | conflicting Tcl/Tk installations, and makes it much easier for Python |
| 1319 | to ensure that Tcl/Tk can find all its files. |
| 1320 | |
| 1321 | [This was new in 1.6] The Windows installer now installs by default in |
| 1322 | \Python20\ on the default volume, instead of \Program Files\Python-2.0\. |
| 1323 | |
Guido van Rossum | f62ed9c | 2000-09-26 11:16:10 +0000 | [diff] [blame] | 1324 | |
| 1325 | Updates to the changes between 1.5.2 and 1.6 |
| 1326 | -------------------------------------------- |
| 1327 | |
| 1328 | The 1.6 NEWS file can't be changed after the release is done, so here |
| 1329 | is some late-breaking news: |
| 1330 | |
| 1331 | New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(), |
| 1332 | and changes to getlocale() and setlocale(). |
| 1333 | |
| 1334 | The new module is now enabled per default. |
| 1335 | |
| 1336 | It is not true that the encodings codecs cannot be used for normal |
| 1337 | strings: the string.encode() (which is also present on 8-bit strings |
| 1338 | !) allows using them for 8-bit strings too, e.g. to convert files from |
| 1339 | cp1252 (Windows) to latin-1 or vice-versa. |
| 1340 | |
| 1341 | Japanese codecs are available from Tamito KAJIYAMA: |
| 1342 | http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/ |
| 1343 | |
| 1344 | |
Guido van Rossum | ab9d6f0 | 1998-08-10 22:01:13 +0000 | [diff] [blame] | 1345 | ====================================================================== |