| """A collection of string operations (most are no longer used). |
| |
| Warning: most of the code you see here isn't normally used nowadays. |
| Beginning with Python 1.6, many of these functions are implemented as |
| methods on the standard string object. They used to be implemented by |
| a built-in module called strop, but strop is now obsolete itself. |
| |
| Public module variables: |
| |
| whitespace -- a string containing all characters considered whitespace |
| lowercase -- a string containing all characters considered lowercase letters |
| uppercase -- a string containing all characters considered uppercase letters |
| letters -- a string containing all characters considered letters |
| digits -- a string containing all characters considered decimal digits |
| hexdigits -- a string containing all characters considered hexadecimal digits |
| octdigits -- a string containing all characters considered octal digits |
| punctuation -- a string containing all characters considered punctuation |
| printable -- a string containing all characters considered printable |
| |
| """ |
| |
| # Some strings for ctype-style character classification |
| whitespace = ' \t\n\r\v\f' |
| lowercase = 'abcdefghijklmnopqrstuvwxyz' |
| uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' |
| letters = lowercase + uppercase |
| ascii_lowercase = lowercase |
| ascii_uppercase = uppercase |
| ascii_letters = ascii_lowercase + ascii_uppercase |
| digits = '0123456789' |
| hexdigits = digits + 'abcdef' + 'ABCDEF' |
| octdigits = '01234567' |
| punctuation = """!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~""" |
| printable = digits + letters + punctuation + whitespace |
| |
| # Case conversion helpers |
| # Use str to convert Unicode literal in case of -U |
| # Note that Cookie.py bogusly uses _idmap :( |
| l = map(chr, xrange(256)) |
| _idmap = str('').join(l) |
| del l |
| |
| # Functions which aren't available as string methods. |
| |
| # Capitalize the words in a string, e.g. " aBc dEf " -> "Abc Def". |
| # See also regsub.capwords(). |
| def capwords(s, sep=None): |
| """capwords(s, [sep]) -> string |
| |
| Split the argument into words using split, capitalize each |
| word using capitalize, and join the capitalized words using |
| join. Note that this replaces runs of whitespace characters by |
| a single space. |
| |
| """ |
| return (sep or ' ').join([x.capitalize() for x in s.split(sep)]) |
| |
| |
| # Construct a translation string |
| _idmapL = None |
| def maketrans(fromstr, tostr): |
| """maketrans(frm, to) -> string |
| |
| Return a translation table (a string of 256 bytes long) |
| suitable for use in string.translate. The strings frm and to |
| must be of the same length. |
| |
| """ |
| if len(fromstr) != len(tostr): |
| raise ValueError, "maketrans arguments must have same length" |
| global _idmapL |
| if not _idmapL: |
| _idmapL = map(None, _idmap) |
| L = _idmapL[:] |
| fromstr = map(ord, fromstr) |
| for i in range(len(fromstr)): |
| L[fromstr[i]] = tostr[i] |
| return ''.join(L) |
| |
| |
| |
| import re as _re |
| |
| class Template(unicode): |
| """A string class for supporting $-substitutions.""" |
| __slots__ = [] |
| |
| # Search for $$, $identifier, ${identifier}, and any bare $'s |
| pattern = _re.compile(r""" |
| # Match exactly two $'s -- this is the escape sequence |
| (?P<escaped>\${2})| |
| # Match a $ followed by a Python identifier |
| \$(?P<named>[_a-z][_a-z0-9]*)| |
| # Match a $ followed by a brace delimited identifier |
| \${(?P<braced>[_a-z][_a-z0-9]*)}| |
| # Match any other $'s |
| (?P<bogus>\$) |
| """, _re.IGNORECASE | _re.VERBOSE) |
| |
| def __mod__(self, mapping): |
| def convert(mo): |
| groups = mo.groupdict() |
| if groups.get('escaped') is not None: |
| return '$' |
| if groups.get('bogus') is not None: |
| raise ValueError('Invalid placeholder at index %d' % |
| mo.start('bogus')) |
| val = mapping[groups.get('named') or groups.get('braced')] |
| return unicode(val) |
| return self.pattern.sub(convert, self) |
| |
| |
| class SafeTemplate(Template): |
| """A string class for supporting $-substitutions. |
| |
| This class is 'safe' in the sense that you will never get KeyErrors if |
| there are placeholders missing from the interpolation dictionary. In that |
| case, you will get the original placeholder in the value string. |
| """ |
| __slots__ = [] |
| |
| def __mod__(self, mapping): |
| def convert(mo): |
| groups = mo.groupdict() |
| if groups.get('escaped') is not None: |
| return '$' |
| if groups.get('bogus') is not None: |
| raise ValueError('Invalid placeholder at index %d' % |
| mo.start('bogus')) |
| named = groups.get('named') |
| if named is not None: |
| try: |
| return unicode(mapping[named]) |
| except KeyError: |
| return '$' + named |
| braced = groups.get('braced') |
| try: |
| return unicode(mapping[braced]) |
| except KeyError: |
| return '${' + braced + '}' |
| return self.pattern.sub(convert, self) |
| |
| |
| |
| # NOTE: Everything below here is deprecated. Use string methods instead. |
| # This stuff will go away in Python 3.0. |
| |
| # Backward compatible names for exceptions |
| index_error = ValueError |
| atoi_error = ValueError |
| atof_error = ValueError |
| atol_error = ValueError |
| |
| # convert UPPER CASE letters to lower case |
| def lower(s): |
| """lower(s) -> string |
| |
| Return a copy of the string s converted to lowercase. |
| |
| """ |
| return s.lower() |
| |
| # Convert lower case letters to UPPER CASE |
| def upper(s): |
| """upper(s) -> string |
| |
| Return a copy of the string s converted to uppercase. |
| |
| """ |
| return s.upper() |
| |
| # Swap lower case letters and UPPER CASE |
| def swapcase(s): |
| """swapcase(s) -> string |
| |
| Return a copy of the string s with upper case characters |
| converted to lowercase and vice versa. |
| |
| """ |
| return s.swapcase() |
| |
| # Strip leading and trailing tabs and spaces |
| def strip(s, chars=None): |
| """strip(s [,chars]) -> string |
| |
| Return a copy of the string s with leading and trailing |
| whitespace removed. |
| If chars is given and not None, remove characters in chars instead. |
| If chars is unicode, S will be converted to unicode before stripping. |
| |
| """ |
| return s.strip(chars) |
| |
| # Strip leading tabs and spaces |
| def lstrip(s, chars=None): |
| """lstrip(s [,chars]) -> string |
| |
| Return a copy of the string s with leading whitespace removed. |
| If chars is given and not None, remove characters in chars instead. |
| |
| """ |
| return s.lstrip(chars) |
| |
| # Strip trailing tabs and spaces |
| def rstrip(s, chars=None): |
| """rstrip(s [,chars]) -> string |
| |
| Return a copy of the string s with trailing whitespace removed. |
| If chars is given and not None, remove characters in chars instead. |
| |
| """ |
| return s.rstrip(chars) |
| |
| |
| # Split a string into a list of space/tab-separated words |
| def split(s, sep=None, maxsplit=-1): |
| """split(s [,sep [,maxsplit]]) -> list of strings |
| |
| Return a list of the words in the string s, using sep as the |
| delimiter string. If maxsplit is given, splits at no more than |
| maxsplit places (resulting in at most maxsplit+1 words). If sep |
| is not specified, any whitespace string is a separator. |
| |
| (split and splitfields are synonymous) |
| |
| """ |
| return s.split(sep, maxsplit) |
| splitfields = split |
| |
| # Split a string into a list of space/tab-separated words |
| def rsplit(s, sep=None, maxsplit=-1): |
| """rsplit(s [,sep [,maxsplit]]) -> list of strings |
| |
| Return a list of the words in the string s, using sep as the |
| delimiter string, starting at the end of the string and working |
| to the front. If maxsplit is given, at most maxsplit splits are |
| done. If sep is not specified or is None, any whitespace string |
| is a separator. |
| """ |
| return s.rsplit(sep, maxsplit) |
| |
| # Join fields with optional separator |
| def join(words, sep = ' '): |
| """join(list [,sep]) -> string |
| |
| Return a string composed of the words in list, with |
| intervening occurrences of sep. The default separator is a |
| single space. |
| |
| (joinfields and join are synonymous) |
| |
| """ |
| return sep.join(words) |
| joinfields = join |
| |
| # Find substring, raise exception if not found |
| def index(s, *args): |
| """index(s, sub [,start [,end]]) -> int |
| |
| Like find but raises ValueError when the substring is not found. |
| |
| """ |
| return s.index(*args) |
| |
| # Find last substring, raise exception if not found |
| def rindex(s, *args): |
| """rindex(s, sub [,start [,end]]) -> int |
| |
| Like rfind but raises ValueError when the substring is not found. |
| |
| """ |
| return s.rindex(*args) |
| |
| # Count non-overlapping occurrences of substring |
| def count(s, *args): |
| """count(s, sub[, start[,end]]) -> int |
| |
| Return the number of occurrences of substring sub in string |
| s[start:end]. Optional arguments start and end are |
| interpreted as in slice notation. |
| |
| """ |
| return s.count(*args) |
| |
| # Find substring, return -1 if not found |
| def find(s, *args): |
| """find(s, sub [,start [,end]]) -> in |
| |
| Return the lowest index in s where substring sub is found, |
| such that sub is contained within s[start,end]. Optional |
| arguments start and end are interpreted as in slice notation. |
| |
| Return -1 on failure. |
| |
| """ |
| return s.find(*args) |
| |
| # Find last substring, return -1 if not found |
| def rfind(s, *args): |
| """rfind(s, sub [,start [,end]]) -> int |
| |
| Return the highest index in s where substring sub is found, |
| such that sub is contained within s[start,end]. Optional |
| arguments start and end are interpreted as in slice notation. |
| |
| Return -1 on failure. |
| |
| """ |
| return s.rfind(*args) |
| |
| # for a bit of speed |
| _float = float |
| _int = int |
| _long = long |
| |
| # Convert string to float |
| def atof(s): |
| """atof(s) -> float |
| |
| Return the floating point number represented by the string s. |
| |
| """ |
| return _float(s) |
| |
| |
| # Convert string to integer |
| def atoi(s , base=10): |
| """atoi(s [,base]) -> int |
| |
| Return the integer represented by the string s in the given |
| base, which defaults to 10. The string s must consist of one |
| or more digits, possibly preceded by a sign. If base is 0, it |
| is chosen from the leading characters of s, 0 for octal, 0x or |
| 0X for hexadecimal. If base is 16, a preceding 0x or 0X is |
| accepted. |
| |
| """ |
| return _int(s, base) |
| |
| |
| # Convert string to long integer |
| def atol(s, base=10): |
| """atol(s [,base]) -> long |
| |
| Return the long integer represented by the string s in the |
| given base, which defaults to 10. The string s must consist |
| of one or more digits, possibly preceded by a sign. If base |
| is 0, it is chosen from the leading characters of s, 0 for |
| octal, 0x or 0X for hexadecimal. If base is 16, a preceding |
| 0x or 0X is accepted. A trailing L or l is not accepted, |
| unless base is 0. |
| |
| """ |
| return _long(s, base) |
| |
| |
| # Left-justify a string |
| def ljust(s, width, *args): |
| """ljust(s, width[, fillchar]) -> string |
| |
| Return a left-justified version of s, in a field of the |
| specified width, padded with spaces as needed. The string is |
| never truncated. If specified the fillchar is used instead of spaces. |
| |
| """ |
| return s.ljust(width, *args) |
| |
| # Right-justify a string |
| def rjust(s, width, *args): |
| """rjust(s, width[, fillchar]) -> string |
| |
| Return a right-justified version of s, in a field of the |
| specified width, padded with spaces as needed. The string is |
| never truncated. If specified the fillchar is used instead of spaces. |
| |
| """ |
| return s.rjust(width, *args) |
| |
| # Center a string |
| def center(s, width, *args): |
| """center(s, width[, fillchar]) -> string |
| |
| Return a center version of s, in a field of the specified |
| width. padded with spaces as needed. The string is never |
| truncated. If specified the fillchar is used instead of spaces. |
| |
| """ |
| return s.center(width, *args) |
| |
| # Zero-fill a number, e.g., (12, 3) --> '012' and (-3, 3) --> '-03' |
| # Decadent feature: the argument may be a string or a number |
| # (Use of this is deprecated; it should be a string as with ljust c.s.) |
| def zfill(x, width): |
| """zfill(x, width) -> string |
| |
| Pad a numeric string x with zeros on the left, to fill a field |
| of the specified width. The string x is never truncated. |
| |
| """ |
| if not isinstance(x, basestring): |
| x = repr(x) |
| return x.zfill(width) |
| |
| # Expand tabs in a string. |
| # Doesn't take non-printing chars into account, but does understand \n. |
| def expandtabs(s, tabsize=8): |
| """expandtabs(s [,tabsize]) -> string |
| |
| Return a copy of the string s with all tab characters replaced |
| by the appropriate number of spaces, depending on the current |
| column, and the tabsize (default 8). |
| |
| """ |
| return s.expandtabs(tabsize) |
| |
| # Character translation through look-up table. |
| def translate(s, table, deletions=""): |
| """translate(s,table [,deletions]) -> string |
| |
| Return a copy of the string s, where all characters occurring |
| in the optional argument deletions are removed, and the |
| remaining characters have been mapped through the given |
| translation table, which must be a string of length 256. The |
| deletions argument is not allowed for Unicode strings. |
| |
| """ |
| if deletions: |
| return s.translate(table, deletions) |
| else: |
| # Add s[:0] so that if s is Unicode and table is an 8-bit string, |
| # table is converted to Unicode. This means that table *cannot* |
| # be a dictionary -- for that feature, use u.translate() directly. |
| return s.translate(table + s[:0]) |
| |
| # Capitalize a string, e.g. "aBc dEf" -> "Abc def". |
| def capitalize(s): |
| """capitalize(s) -> string |
| |
| Return a copy of the string s with only its first character |
| capitalized. |
| |
| """ |
| return s.capitalize() |
| |
| # Substring replacement (global) |
| def replace(s, old, new, maxsplit=-1): |
| """replace (str, old, new[, maxsplit]) -> string |
| |
| Return a copy of string str with all occurrences of substring |
| old replaced by new. If the optional argument maxsplit is |
| given, only the first maxsplit occurrences are replaced. |
| |
| """ |
| return s.replace(old, new, maxsplit) |
| |
| |
| # Try importing optional built-in module "strop" -- if it exists, |
| # it redefines some string operations that are 100-1000 times faster. |
| # It also defines values for whitespace, lowercase and uppercase |
| # that match <ctype.h>'s definitions. |
| |
| try: |
| from strop import maketrans, lowercase, uppercase, whitespace |
| letters = lowercase + uppercase |
| except ImportError: |
| pass # Use the original versions |