209 lines
7.0 KiB
Python
209 lines
7.0 KiB
Python
"""A collection of string constants.
|
|
|
|
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
|
|
l = map(chr, range(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".
|
|
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 _multimap:
|
|
"""Helper class for combining multiple mappings.
|
|
|
|
Used by .{safe_,}substitute() to combine the mapping and keyword
|
|
arguments.
|
|
"""
|
|
def __init__(self, primary, secondary):
|
|
self._primary = primary
|
|
self._secondary = secondary
|
|
|
|
def __getitem__(self, key):
|
|
try:
|
|
return self._primary[key]
|
|
except KeyError:
|
|
return self._secondary[key]
|
|
|
|
|
|
class _TemplateMetaclass(type):
|
|
pattern = r"""
|
|
%(delim)s(?:
|
|
(?P<escaped>%(delim)s) | # Escape sequence of two delimiters
|
|
(?P<named>%(id)s) | # delimiter and a Python identifier
|
|
{(?P<braced>%(id)s)} | # delimiter and a braced identifier
|
|
(?P<invalid>) # Other ill-formed delimiter exprs
|
|
)
|
|
"""
|
|
|
|
def __init__(cls, name, bases, dct):
|
|
super(_TemplateMetaclass, cls).__init__(name, bases, dct)
|
|
if 'pattern' in dct:
|
|
pattern = cls.pattern
|
|
else:
|
|
pattern = _TemplateMetaclass.pattern % {
|
|
'delim' : _re.escape(cls.delimiter),
|
|
'id' : cls.idpattern,
|
|
}
|
|
cls.pattern = _re.compile(pattern, _re.IGNORECASE | _re.VERBOSE)
|
|
|
|
|
|
class Template(metaclass=_TemplateMetaclass):
|
|
"""A string class for supporting $-substitutions."""
|
|
|
|
delimiter = '$'
|
|
idpattern = r'[_a-z][_a-z0-9]*'
|
|
|
|
def __init__(self, template):
|
|
self.template = template
|
|
|
|
# Search for $$, $identifier, ${identifier}, and any bare $'s
|
|
|
|
def _invalid(self, mo):
|
|
i = mo.start('invalid')
|
|
lines = self.template[:i].splitlines(True)
|
|
if not lines:
|
|
colno = 1
|
|
lineno = 1
|
|
else:
|
|
colno = i - len(''.join(lines[:-1]))
|
|
lineno = len(lines)
|
|
raise ValueError('Invalid placeholder in string: line %d, col %d' %
|
|
(lineno, colno))
|
|
|
|
def substitute(self, *args, **kws):
|
|
if len(args) > 1:
|
|
raise TypeError('Too many positional arguments')
|
|
if not args:
|
|
mapping = kws
|
|
elif kws:
|
|
mapping = _multimap(kws, args[0])
|
|
else:
|
|
mapping = args[0]
|
|
# Helper function for .sub()
|
|
def convert(mo):
|
|
# Check the most common path first.
|
|
named = mo.group('named') or mo.group('braced')
|
|
if named is not None:
|
|
val = mapping[named]
|
|
# We use this idiom instead of str() because the latter will
|
|
# fail if val is a Unicode containing non-ASCII characters.
|
|
return '%s' % (val,)
|
|
if mo.group('escaped') is not None:
|
|
return self.delimiter
|
|
if mo.group('invalid') is not None:
|
|
self._invalid(mo)
|
|
raise ValueError('Unrecognized named group in pattern',
|
|
self.pattern)
|
|
return self.pattern.sub(convert, self.template)
|
|
|
|
def safe_substitute(self, *args, **kws):
|
|
if len(args) > 1:
|
|
raise TypeError('Too many positional arguments')
|
|
if not args:
|
|
mapping = kws
|
|
elif kws:
|
|
mapping = _multimap(kws, args[0])
|
|
else:
|
|
mapping = args[0]
|
|
# Helper function for .sub()
|
|
def convert(mo):
|
|
named = mo.group('named')
|
|
if named is not None:
|
|
try:
|
|
# We use this idiom instead of str() because the latter
|
|
# will fail if val is a Unicode containing non-ASCII
|
|
return '%s' % (mapping[named],)
|
|
except KeyError:
|
|
return self.delimiter + named
|
|
braced = mo.group('braced')
|
|
if braced is not None:
|
|
try:
|
|
return '%s' % (mapping[braced],)
|
|
except KeyError:
|
|
return self.delimiter + '{' + braced + '}'
|
|
if mo.group('escaped') is not None:
|
|
return self.delimiter
|
|
if mo.group('invalid') is not None:
|
|
return self.delimiter
|
|
raise ValueError('Unrecognized named group in pattern',
|
|
self.pattern)
|
|
return self.pattern.sub(convert, self.template)
|
|
|
|
|
|
# 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
|
|
except ImportError:
|
|
pass # Use the original versions
|