| # module 'string' -- A collection of string operations | |
| # Warning: most of the code you see here isn't normally used nowadays. 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. | |
| """Common string manipulations. | |
| 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 | |
| """ | |
| from warnings import warnpy3k | |
| warnpy3k("the stringold module has been removed in Python 3.0", stacklevel=2) | |
| del warnpy3k | |
| # Some strings for ctype-style character classification | |
| whitespace = ' \t\n\r\v\f' | |
| lowercase = 'abcdefghijklmnopqrstuvwxyz' | |
| uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' | |
| letters = lowercase + uppercase | |
| digits = '0123456789' | |
| hexdigits = digits + 'abcdef' + 'ABCDEF' | |
| octdigits = '01234567' | |
| # Case conversion helpers | |
| _idmap = '' | |
| for i in range(256): _idmap = _idmap + chr(i) | |
| del i | |
| # 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): | |
| """strip(s) -> string | |
| Return a copy of the string s with leading and trailing | |
| whitespace removed. | |
| """ | |
| return s.strip() | |
| # Strip leading tabs and spaces | |
| def lstrip(s): | |
| """lstrip(s) -> string | |
| Return a copy of the string s with leading whitespace removed. | |
| """ | |
| return s.lstrip() | |
| # Strip trailing tabs and spaces | |
| def rstrip(s): | |
| """rstrip(s) -> string | |
| Return a copy of the string s with trailing whitespace | |
| removed. | |
| """ | |
| return s.rstrip() | |
| # Split a string into a list of space/tab-separated words | |
| def split(s, sep=None, maxsplit=0): | |
| """split(str [,sep [,maxsplit]]) -> list of strings | |
| Return a list of the words in the string s, using sep as the | |
| delimiter string. If maxsplit is nonzero, splits into at most | |
| maxsplit words If sep is not specified, any whitespace string | |
| is a separator. Maxsplit defaults to 0. | |
| (split and splitfields are synonymous) | |
| """ | |
| return s.split(sep, maxsplit) | |
| splitfields = split | |
| # 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 | |
| # for a little bit of speed | |
| _apply = apply | |
| # 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 _apply(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 _apply(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 _apply(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 _apply(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 _apply(s.rfind, args) | |
| # for a bit of speed | |
| _float = float | |
| _int = int | |
| _long = long | |
| _StringType = type('') | |
| # Convert string to float | |
| def atof(s): | |
| """atof(s) -> float | |
| Return the floating point number represented by the string s. | |
| """ | |
| if type(s) == _StringType: | |
| return _float(s) | |
| else: | |
| raise TypeError('argument 1: expected string, %s found' % | |
| type(s).__name__) | |
| # Convert string to integer | |
| def atoi(*args): | |
| """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. | |
| """ | |
| try: | |
| s = args[0] | |
| except IndexError: | |
| raise TypeError('function requires at least 1 argument: %d given' % | |
| len(args)) | |
| # Don't catch type error resulting from too many arguments to int(). The | |
| # error message isn't compatible but the error type is, and this function | |
| # is complicated enough already. | |
| if type(s) == _StringType: | |
| return _apply(_int, args) | |
| else: | |
| raise TypeError('argument 1: expected string, %s found' % | |
| type(s).__name__) | |
| # Convert string to long integer | |
| def atol(*args): | |
| """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. | |
| """ | |
| try: | |
| s = args[0] | |
| except IndexError: | |
| raise TypeError('function requires at least 1 argument: %d given' % | |
| len(args)) | |
| # Don't catch type error resulting from too many arguments to long(). The | |
| # error message isn't compatible but the error type is, and this function | |
| # is complicated enough already. | |
| if type(s) == _StringType: | |
| return _apply(_long, args) | |
| else: | |
| raise TypeError('argument 1: expected string, %s found' % | |
| type(s).__name__) | |
| # Left-justify a string | |
| def ljust(s, width): | |
| """ljust(s, width) -> 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. | |
| """ | |
| n = width - len(s) | |
| if n <= 0: return s | |
| return s + ' '*n | |
| # Right-justify a string | |
| def rjust(s, width): | |
| """rjust(s, width) -> 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. | |
| """ | |
| n = width - len(s) | |
| if n <= 0: return s | |
| return ' '*n + s | |
| # Center a string | |
| def center(s, width): | |
| """center(s, width) -> string | |
| Return a center version of s, in a field of the specified | |
| width. padded with spaces as needed. The string is never | |
| truncated. | |
| """ | |
| n = width - len(s) | |
| if n <= 0: return s | |
| half = n/2 | |
| if n%2 and width%2: | |
| # This ensures that center(center(s, i), j) = center(s, j) | |
| half = half+1 | |
| return ' '*half + s + ' '*(n-half) | |
| # 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 type(x) == type(''): s = x | |
| else: s = repr(x) | |
| n = len(s) | |
| if n >= width: return s | |
| sign = '' | |
| if s[0] in ('-', '+'): | |
| sign, s = s[0], s[1:] | |
| return sign + '0'*(width-n) + s | |
| # 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). | |
| """ | |
| res = line = '' | |
| for c in s: | |
| if c == '\t': | |
| c = ' '*(tabsize - len(line) % tabsize) | |
| line = line + c | |
| if c == '\n': | |
| res = res + line | |
| line = '' | |
| return res + line | |
| # Character translation through look-up table. | |
| def translate(s, table, deletions=""): | |
| """translate(s,table [,deletechars]) -> string | |
| Return a copy of the string s, where all characters occurring | |
| in the optional argument deletechars are removed, and the | |
| remaining characters have been mapped through the given | |
| translation table, which must be a string of length 256. | |
| """ | |
| return s.translate(table, deletions) | |
| # 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() | |
| # Capitalize the words in a string, e.g. " aBc dEf " -> "Abc Def". | |
| 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 join(map(capitalize, s.split(sep)), sep or ' ') | |
| # 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 = list(_idmap) | |
| L = _idmapL[:] | |
| fromstr = map(ord, fromstr) | |
| for i in range(len(fromstr)): | |
| L[fromstr[i]] = tostr[i] | |
| return join(L, "") | |
| # Substring replacement (global) | |
| def replace(s, old, new, maxsplit=0): | |
| """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) | |
| # XXX: transitional | |
| # | |
| # If string objects do not have methods, then we need to use the old string.py | |
| # library, which uses strop for many more things than just the few outlined | |
| # below. | |
| try: | |
| ''.upper | |
| except AttributeError: | |
| from stringold import * | |
| # 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 |