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| 1 | +"""A collection of string operations (most are no longer used). | |
| 2 | + | |
| 3 | +Warning: most of the code you see here isn't normally used nowadays. | |
| 4 | +Beginning with Python 1.6, many of these functions are implemented as | |
| 5 | +methods on the standard string object. They used to be implemented by | |
| 6 | +a built-in module called strop, but strop is now obsolete itself. | |
| 7 | + | |
| 8 | +Public module variables: | |
| 9 | + | |
| 10 | +whitespace -- a string containing all characters considered whitespace | |
| 11 | +lowercase -- a string containing all characters considered lowercase letters | |
| 12 | +uppercase -- a string containing all characters considered uppercase letters | |
| 13 | +letters -- a string containing all characters considered letters | |
| 14 | +digits -- a string containing all characters considered decimal digits | |
| 15 | +hexdigits -- a string containing all characters considered hexadecimal digits | |
| 16 | +octdigits -- a string containing all characters considered octal digits | |
| 17 | +punctuation -- a string containing all characters considered punctuation | |
| 18 | +printable -- a string containing all characters considered printable | |
| 19 | + | |
| 20 | +""" | |
| 21 | + | |
| 22 | +# Some strings for ctype-style character classification | |
| 23 | +whitespace = ' \t\n\r\v\f' | |
| 24 | +lowercase = 'abcdefghijklmnopqrstuvwxyz' | |
| 25 | +uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' | |
| 26 | +letters = lowercase + uppercase | |
| 27 | +ascii_lowercase = lowercase | |
| 28 | +ascii_uppercase = uppercase | |
| 29 | +ascii_letters = ascii_lowercase + ascii_uppercase | |
| 30 | +digits = '0123456789' | |
| 31 | +hexdigits = digits + 'abcdef' + 'ABCDEF' | |
| 32 | +octdigits = '01234567' | |
| 33 | +punctuation = """!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~""" | |
| 34 | +printable = digits + letters + punctuation + whitespace | |
| 35 | + | |
| 36 | +# Case conversion helpers | |
| 37 | +# Use str to convert Unicode literal in case of -U | |
| 38 | +l = map(chr, xrange(256)) | |
| 39 | +_idmap = str('').join(l) | |
| 40 | +del l | |
| 41 | + | |
| 42 | +# Functions which aren't available as string methods. | |
| 43 | + | |
| 44 | +# Capitalize the words in a string, e.g. " aBc dEf " -> "Abc Def". | |
| 45 | +def capwords(s, sep=None): | |
| 46 | + """capwords(s, [sep]) -> string | |
| 47 | + | |
| 48 | + Split the argument into words using split, capitalize each | |
| 49 | + word using capitalize, and join the capitalized words using | |
| 50 | + join. Note that this replaces runs of whitespace characters by | |
| 51 | + a single space. | |
| 52 | + | |
| 53 | + """ | |
| 54 | + return (sep or ' ').join([x.capitalize() for x in s.split(sep)]) | |
| 55 | + | |
| 56 | + | |
| 57 | +# Construct a translation string | |
| 58 | +_idmapL = None | |
| 59 | +def maketrans(fromstr, tostr): | |
| 60 | + """maketrans(frm, to) -> string | |
| 61 | + | |
| 62 | + Return a translation table (a string of 256 bytes long) | |
| 63 | + suitable for use in string.translate. The strings frm and to | |
| 64 | + must be of the same length. | |
| 65 | + | |
| 66 | + """ | |
| 67 | + if len(fromstr) != len(tostr): | |
| 68 | + raise ValueError, "maketrans arguments must have same length" | |
| 69 | + global _idmapL | |
| 70 | + if not _idmapL: | |
| 71 | + _idmapL = map(None, _idmap) | |
| 72 | + L = _idmapL[:] | |
| 73 | + fromstr = map(ord, fromstr) | |
| 74 | + for i in range(len(fromstr)): | |
| 75 | + L[fromstr[i]] = tostr[i] | |
| 76 | + return ''.join(L) | |
| 77 | + | |
| 78 | + | |
| 79 | + | |
| 80 | +#################################################################### | |
| 81 | +import re as _re | |
| 82 | + | |
| 83 | +class _multimap: | |
| 84 | + """Helper class for combining multiple mappings. | |
| 85 | + | |
| 86 | + Used by .{safe_,}substitute() to combine the mapping and keyword | |
| 87 | + arguments. | |
| 88 | + """ | |
| 89 | + def __init__(self, primary, secondary): | |
| 90 | + self._primary = primary | |
| 91 | + self._secondary = secondary | |
| 92 | + | |
| 93 | + def __getitem__(self, key): | |
| 94 | + try: | |
| 95 | + return self._primary[key] | |
| 96 | + except KeyError: | |
| 97 | + return self._secondary[key] | |
| 98 | + | |
| 99 | + | |
| 100 | +class _TemplateMetaclass(type): | |
| 101 | + pattern = r""" | |
| 102 | + %(delim)s(?: | |
| 103 | + (?P<escaped>%(delim)s) | # Escape sequence of two delimiters | |
| 104 | + (?P<named>%(id)s) | # delimiter and a Python identifier | |
| 105 | + {(?P<braced>%(id)s)} | # delimiter and a braced identifier | |
| 106 | + (?P<invalid>) # Other ill-formed delimiter exprs | |
| 107 | + ) | |
| 108 | + """ | |
| 109 | + | |
| 110 | + def __init__(cls, name, bases, dct): | |
| 111 | + super(_TemplateMetaclass, cls).__init__(name, bases, dct) | |
| 112 | + if 'pattern' in dct: | |
| 113 | + pattern = cls.pattern | |
| 114 | + else: | |
| 115 | + pattern = _TemplateMetaclass.pattern % { | |
| 116 | + 'delim' : _re.escape(cls.delimiter), | |
| 117 | + 'id' : cls.idpattern, | |
| 118 | + } | |
| 119 | + cls.pattern = _re.compile(pattern, _re.IGNORECASE | _re.VERBOSE) | |
| 120 | + | |
| 121 | + | |
| 122 | +class Template: | |
| 123 | + """A string class for supporting $-substitutions.""" | |
| 124 | + __metaclass__ = _TemplateMetaclass | |
| 125 | + | |
| 126 | + delimiter = '$' | |
| 127 | + idpattern = r'[_a-z][_a-z0-9]*' | |
| 128 | + | |
| 129 | + def __init__(self, template): | |
| 130 | + self.template = template | |
| 131 | + | |
| 132 | + # Search for $$, $identifier, ${identifier}, and any bare $'s | |
| 133 | + | |
| 134 | + def _invalid(self, mo): | |
| 135 | + i = mo.start('invalid') | |
| 136 | + lines = self.template[:i].splitlines(True) | |
| 137 | + if not lines: | |
| 138 | + colno = 1 | |
| 139 | + lineno = 1 | |
| 140 | + else: | |
| 141 | + colno = i - len(''.join(lines[:-1])) | |
| 142 | + lineno = len(lines) | |
| 143 | + raise ValueError('Invalid placeholder in string: line %d, col %d' % | |
| 144 | + (lineno, colno)) | |
| 145 | + | |
| 146 | + def substitute(self, *args, **kws): | |
| 147 | + if len(args) > 1: | |
| 148 | + raise TypeError('Too many positional arguments') | |
| 149 | + if not args: | |
| 150 | + mapping = kws | |
| 151 | + elif kws: | |
| 152 | + mapping = _multimap(kws, args[0]) | |
| 153 | + else: | |
| 154 | + mapping = args[0] | |
| 155 | + # Helper function for .sub() | |
| 156 | + def convert(mo): | |
| 157 | + # Check the most common path first. | |
| 158 | + named = mo.group('named') or mo.group('braced') | |
| 159 | + if named is not None: | |
| 160 | + val = mapping[named] | |
| 161 | + # We use this idiom instead of str() because the latter will | |
| 162 | + # fail if val is a Unicode containing non-ASCII characters. | |
| 163 | + return '%s' % (val,) | |
| 164 | + if mo.group('escaped') is not None: | |
| 165 | + return self.delimiter | |
| 166 | + if mo.group('invalid') is not None: | |
| 167 | + self._invalid(mo) | |
| 168 | + raise ValueError('Unrecognized named group in pattern', | |
| 169 | + self.pattern) | |
| 170 | + return self.pattern.sub(convert, self.template) | |
| 171 | + | |
| 172 | + def safe_substitute(self, *args, **kws): | |
| 173 | + if len(args) > 1: | |
| 174 | + raise TypeError('Too many positional arguments') | |
| 175 | + if not args: | |
| 176 | + mapping = kws | |
| 177 | + elif kws: | |
| 178 | + mapping = _multimap(kws, args[0]) | |
| 179 | + else: | |
| 180 | + mapping = args[0] | |
| 181 | + # Helper function for .sub() | |
| 182 | + def convert(mo): | |
| 183 | + named = mo.group('named') | |
| 184 | + if named is not None: | |
| 185 | + try: | |
| 186 | + # We use this idiom instead of str() because the latter | |
| 187 | + # will fail if val is a Unicode containing non-ASCII | |
| 188 | + return '%s' % (mapping[named],) | |
| 189 | + except KeyError: | |
| 190 | + return self.delimiter + named | |
| 191 | + braced = mo.group('braced') | |
| 192 | + if braced is not None: | |
| 193 | + try: | |
| 194 | + return '%s' % (mapping[braced],) | |
| 195 | + except KeyError: | |
| 196 | + return self.delimiter + '{' + braced + '}' | |
| 197 | + if mo.group('escaped') is not None: | |
| 198 | + return self.delimiter | |
| 199 | + if mo.group('invalid') is not None: | |
| 200 | + return self.delimiter | |
| 201 | + raise ValueError('Unrecognized named group in pattern', | |
| 202 | + self.pattern) | |
| 203 | + return self.pattern.sub(convert, self.template) | |
| 204 | + | |
| 205 | + | |
| 206 | + | |
| 207 | +#################################################################### | |
| 208 | +# NOTE: Everything below here is deprecated. Use string methods instead. | |
| 209 | +# This stuff will go away in Python 3.0. | |
| 210 | + | |
| 211 | +# Backward compatible names for exceptions | |
| 212 | +index_error = ValueError | |
| 213 | +atoi_error = ValueError | |
| 214 | +atof_error = ValueError | |
| 215 | +atol_error = ValueError | |
| 216 | + | |
| 217 | +# convert UPPER CASE letters to lower case | |
| 218 | +def lower(s): | |
| 219 | + """lower(s) -> string | |
| 220 | + | |
| 221 | + Return a copy of the string s converted to lowercase. | |
| 222 | + | |
| 223 | + """ | |
| 224 | + return s.lower() | |
| 225 | + | |
| 226 | +# Convert lower case letters to UPPER CASE | |
| 227 | +def upper(s): | |
| 228 | + """upper(s) -> string | |
| 229 | + | |
| 230 | + Return a copy of the string s converted to uppercase. | |
| 231 | + | |
| 232 | + """ | |
| 233 | + return s.upper() | |
| 234 | + | |
| 235 | +# Swap lower case letters and UPPER CASE | |
| 236 | +def swapcase(s): | |
| 237 | + """swapcase(s) -> string | |
| 238 | + | |
| 239 | + Return a copy of the string s with upper case characters | |
| 240 | + converted to lowercase and vice versa. | |
| 241 | + | |
| 242 | + """ | |
| 243 | + return s.swapcase() | |
| 244 | + | |
| 245 | +# Strip leading and trailing tabs and spaces | |
| 246 | +def strip(s, chars=None): | |
| 247 | + """strip(s [,chars]) -> string | |
| 248 | + | |
| 249 | + Return a copy of the string s with leading and trailing | |
| 250 | + whitespace removed. | |
| 251 | + If chars is given and not None, remove characters in chars instead. | |
| 252 | + If chars is unicode, S will be converted to unicode before stripping. | |
| 253 | + | |
| 254 | + """ | |
| 255 | + return s.strip(chars) | |
| 256 | + | |
| 257 | +# Strip leading tabs and spaces | |
| 258 | +def lstrip(s, chars=None): | |
| 259 | + """lstrip(s [,chars]) -> string | |
| 260 | + | |
| 261 | + Return a copy of the string s with leading whitespace removed. | |
| 262 | + If chars is given and not None, remove characters in chars instead. | |
| 263 | + | |
| 264 | + """ | |
| 265 | + return s.lstrip(chars) | |
| 266 | + | |
| 267 | +# Strip trailing tabs and spaces | |
| 268 | +def rstrip(s, chars=None): | |
| 269 | + """rstrip(s [,chars]) -> string | |
| 270 | + | |
| 271 | + Return a copy of the string s with trailing whitespace removed. | |
| 272 | + If chars is given and not None, remove characters in chars instead. | |
| 273 | + | |
| 274 | + """ | |
| 275 | + return s.rstrip(chars) | |
| 276 | + | |
| 277 | + | |
| 278 | +# Split a string into a list of space/tab-separated words | |
| 279 | +def split(s, sep=None, maxsplit=-1): | |
| 280 | + """split(s [,sep [,maxsplit]]) -> list of strings | |
| 281 | + | |
| 282 | + Return a list of the words in the string s, using sep as the | |
| 283 | + delimiter string. If maxsplit is given, splits at no more than | |
| 284 | + maxsplit places (resulting in at most maxsplit+1 words). If sep | |
| 285 | + is not specified or is None, any whitespace string is a separator. | |
| 286 | + | |
| 287 | + (split and splitfields are synonymous) | |
| 288 | + | |
| 289 | + """ | |
| 290 | + return s.split(sep, maxsplit) | |
| 291 | +splitfields = split | |
| 292 | + | |
| 293 | +# Split a string into a list of space/tab-separated words | |
| 294 | +def rsplit(s, sep=None, maxsplit=-1): | |
| 295 | + """rsplit(s [,sep [,maxsplit]]) -> list of strings | |
| 296 | + | |
| 297 | + Return a list of the words in the string s, using sep as the | |
| 298 | + delimiter string, starting at the end of the string and working | |
| 299 | + to the front. If maxsplit is given, at most maxsplit splits are | |
| 300 | + done. If sep is not specified or is None, any whitespace string | |
| 301 | + is a separator. | |
| 302 | + """ | |
| 303 | + return s.rsplit(sep, maxsplit) | |
| 304 | + | |
| 305 | +# Join fields with optional separator | |
| 306 | +def join(words, sep = ' '): | |
| 307 | + """join(list [,sep]) -> string | |
| 308 | + | |
| 309 | + Return a string composed of the words in list, with | |
| 310 | + intervening occurrences of sep. The default separator is a | |
| 311 | + single space. | |
| 312 | + | |
| 313 | + (joinfields and join are synonymous) | |
| 314 | + | |
| 315 | + """ | |
| 316 | + return sep.join(words) | |
| 317 | +joinfields = join | |
| 318 | + | |
| 319 | +# Find substring, raise exception if not found | |
| 320 | +def index(s, *args): | |
| 321 | + """index(s, sub [,start [,end]]) -> int | |
| 322 | + | |
| 323 | + Like find but raises ValueError when the substring is not found. | |
| 324 | + | |
| 325 | + """ | |
| 326 | + return s.index(*args) | |
| 327 | + | |
| 328 | +# Find last substring, raise exception if not found | |
| 329 | +def rindex(s, *args): | |
| 330 | + """rindex(s, sub [,start [,end]]) -> int | |
| 331 | + | |
| 332 | + Like rfind but raises ValueError when the substring is not found. | |
| 333 | + | |
| 334 | + """ | |
| 335 | + return s.rindex(*args) | |
| 336 | + | |
| 337 | +# Count non-overlapping occurrences of substring | |
| 338 | +def count(s, *args): | |
| 339 | + """count(s, sub[, start[,end]]) -> int | |
| 340 | + | |
| 341 | + Return the number of occurrences of substring sub in string | |
| 342 | + s[start:end]. Optional arguments start and end are | |
| 343 | + interpreted as in slice notation. | |
| 344 | + | |
| 345 | + """ | |
| 346 | + return s.count(*args) | |
| 347 | + | |
| 348 | +# Find substring, return -1 if not found | |
| 349 | +def find(s, *args): | |
| 350 | + """find(s, sub [,start [,end]]) -> in | |
| 351 | + | |
| 352 | + Return the lowest index in s where substring sub is found, | |
| 353 | + such that sub is contained within s[start,end]. Optional | |
| 354 | + arguments start and end are interpreted as in slice notation. | |
| 355 | + | |
| 356 | + Return -1 on failure. | |
| 357 | + | |
| 358 | + """ | |
| 359 | + return s.find(*args) | |
| 360 | + | |
| 361 | +# Find last substring, return -1 if not found | |
| 362 | +def rfind(s, *args): | |
| 363 | + """rfind(s, sub [,start [,end]]) -> int | |
| 364 | + | |
| 365 | + Return the highest index in s where substring sub is found, | |
| 366 | + such that sub is contained within s[start,end]. Optional | |
| 367 | + arguments start and end are interpreted as in slice notation. | |
| 368 | + | |
| 369 | + Return -1 on failure. | |
| 370 | + | |
| 371 | + """ | |
| 372 | + return s.rfind(*args) | |
| 373 | + | |
| 374 | +# for a bit of speed | |
| 375 | +_float = float | |
| 376 | +_int = int | |
| 377 | +_long = long | |
| 378 | + | |
| 379 | +# Convert string to float | |
| 380 | +def atof(s): | |
| 381 | + """atof(s) -> float | |
| 382 | + | |
| 383 | + Return the floating point number represented by the string s. | |
| 384 | + | |
| 385 | + """ | |
| 386 | + return _float(s) | |
| 387 | + | |
| 388 | + | |
| 389 | +# Convert string to integer | |
| 390 | +def atoi(s , base=10): | |
| 391 | + """atoi(s [,base]) -> int | |
| 392 | + | |
| 393 | + Return the integer represented by the string s in the given | |
| 394 | + base, which defaults to 10. The string s must consist of one | |
| 395 | + or more digits, possibly preceded by a sign. If base is 0, it | |
| 396 | + is chosen from the leading characters of s, 0 for octal, 0x or | |
| 397 | + 0X for hexadecimal. If base is 16, a preceding 0x or 0X is | |
| 398 | + accepted. | |
| 399 | + | |
| 400 | + """ | |
| 401 | + return _int(s, base) | |
| 402 | + | |
| 403 | + | |
| 404 | +# Convert string to long integer | |
| 405 | +def atol(s, base=10): | |
| 406 | + """atol(s [,base]) -> long | |
| 407 | + | |
| 408 | + Return the long integer represented by the string s in the | |
| 409 | + given base, which defaults to 10. The string s must consist | |
| 410 | + of one or more digits, possibly preceded by a sign. If base | |
| 411 | + is 0, it is chosen from the leading characters of s, 0 for | |
| 412 | + octal, 0x or 0X for hexadecimal. If base is 16, a preceding | |
| 413 | + 0x or 0X is accepted. A trailing L or l is not accepted, | |
| 414 | + unless base is 0. | |
| 415 | + | |
| 416 | + """ | |
| 417 | + return _long(s, base) | |
| 418 | + | |
| 419 | + | |
| 420 | +# Left-justify a string | |
| 421 | +def ljust(s, width, *args): | |
| 422 | + """ljust(s, width[, fillchar]) -> string | |
| 423 | + | |
| 424 | + Return a left-justified version of s, in a field of the | |
| 425 | + specified width, padded with spaces as needed. The string is | |
| 426 | + never truncated. If specified the fillchar is used instead of spaces. | |
| 427 | + | |
| 428 | + """ | |
| 429 | + return s.ljust(width, *args) | |
| 430 | + | |
| 431 | +# Right-justify a string | |
| 432 | +def rjust(s, width, *args): | |
| 433 | + """rjust(s, width[, fillchar]) -> string | |
| 434 | + | |
| 435 | + Return a right-justified version of s, in a field of the | |
| 436 | + specified width, padded with spaces as needed. The string is | |
| 437 | + never truncated. If specified the fillchar is used instead of spaces. | |
| 438 | + | |
| 439 | + """ | |
| 440 | + return s.rjust(width, *args) | |
| 441 | + | |
| 442 | +# Center a string | |
| 443 | +def center(s, width, *args): | |
| 444 | + """center(s, width[, fillchar]) -> string | |
| 445 | + | |
| 446 | + Return a center version of s, in a field of the specified | |
| 447 | + width. padded with spaces as needed. The string is never | |
| 448 | + truncated. If specified the fillchar is used instead of spaces. | |
| 449 | + | |
| 450 | + """ | |
| 451 | + return s.center(width, *args) | |
| 452 | + | |
| 453 | +# Zero-fill a number, e.g., (12, 3) --> '012' and (-3, 3) --> '-03' | |
| 454 | +# Decadent feature: the argument may be a string or a number | |
| 455 | +# (Use of this is deprecated; it should be a string as with ljust c.s.) | |
| 456 | +def zfill(x, width): | |
| 457 | + """zfill(x, width) -> string | |
| 458 | + | |
| 459 | + Pad a numeric string x with zeros on the left, to fill a field | |
| 460 | + of the specified width. The string x is never truncated. | |
| 461 | + | |
| 462 | + """ | |
| 463 | + if not isinstance(x, basestring): | |
| 464 | + x = repr(x) | |
| 465 | + return x.zfill(width) | |
| 466 | + | |
| 467 | +# Expand tabs in a string. | |
| 468 | +# Doesn't take non-printing chars into account, but does understand \n. | |
| 469 | +def expandtabs(s, tabsize=8): | |
| 470 | + """expandtabs(s [,tabsize]) -> string | |
| 471 | + | |
| 472 | + Return a copy of the string s with all tab characters replaced | |
| 473 | + by the appropriate number of spaces, depending on the current | |
| 474 | + column, and the tabsize (default 8). | |
| 475 | + | |
| 476 | + """ | |
| 477 | + return s.expandtabs(tabsize) | |
| 478 | + | |
| 479 | +# Character translation through look-up table. | |
| 480 | +def translate(s, table, deletions=""): | |
| 481 | + """translate(s,table [,deletions]) -> string | |
| 482 | + | |
| 483 | + Return a copy of the string s, where all characters occurring | |
| 484 | + in the optional argument deletions are removed, and the | |
| 485 | + remaining characters have been mapped through the given | |
| 486 | + translation table, which must be a string of length 256. The | |
| 487 | + deletions argument is not allowed for Unicode strings. | |
| 488 | + | |
| 489 | + """ | |
| 490 | + if deletions: | |
| 491 | + return s.translate(table, deletions) | |
| 492 | + else: | |
| 493 | + # Add s[:0] so that if s is Unicode and table is an 8-bit string, | |
| 494 | + # table is converted to Unicode. This means that table *cannot* | |
| 495 | + # be a dictionary -- for that feature, use u.translate() directly. | |
| 496 | + return s.translate(table + s[:0]) | |
| 497 | + | |
| 498 | +# Capitalize a string, e.g. "aBc dEf" -> "Abc def". | |
| 499 | +def capitalize(s): | |
| 500 | + """capitalize(s) -> string | |
| 501 | + | |
| 502 | + Return a copy of the string s with only its first character | |
| 503 | + capitalized. | |
| 504 | + | |
| 505 | + """ | |
| 506 | + return s.capitalize() | |
| 507 | + | |
| 508 | +# Substring replacement (global) | |
| 509 | +def replace(s, old, new, maxsplit=-1): | |
| 510 | + """replace (str, old, new[, maxsplit]) -> string | |
| 511 | + | |
| 512 | + Return a copy of string str with all occurrences of substring | |
| 513 | + old replaced by new. If the optional argument maxsplit is | |
| 514 | + given, only the first maxsplit occurrences are replaced. | |
| 515 | + | |
| 516 | + """ | |
| 517 | + return s.replace(old, new, maxsplit) | |
| 518 | + | |
| 519 | + | |
| 520 | +# Try importing optional built-in module "strop" -- if it exists, | |
| 521 | +# it redefines some string operations that are 100-1000 times faster. | |
| 522 | +# It also defines values for whitespace, lowercase and uppercase | |
| 523 | +# that match <ctype.h>'s definitions. | |
| 524 | + | |
| 525 | +try: | |
| 526 | + from strop import maketrans, lowercase, uppercase, whitespace | |
| 527 | + letters = lowercase + uppercase | |
| 528 | +except ImportError: | |
| 529 | + pass # Use the original versions | |