cpython/Lib/fnmatch.py

108 lines
2.9 KiB
Python

"""Filename matching with shell patterns.
fnmatch(FILENAME, PATTERN) matches according to the local convention.
fnmatchcase(FILENAME, PATTERN) always takes case in account.
The functions operate by translating the pattern into a regular
expression. They cache the compiled regular expressions for speed.
The function translate(PATTERN) returns a regular expression
corresponding to PATTERN. (It does not compile it.)
"""
import re
__all__ = ["fnmatch","fnmatchcase","translate"]
_cache = {}
def fnmatch(name, pat):
"""Test whether FILENAME matches PATTERN.
Patterns are Unix shell style:
* matches everything
? matches any single character
[seq] matches any character in seq
[!seq] matches any char not in seq
An initial period in FILENAME is not special.
Both FILENAME and PATTERN are first case-normalized
if the operating system requires it.
If you don't want this, use fnmatchcase(FILENAME, PATTERN).
"""
import os
name = os.path.normcase(name)
pat = os.path.normcase(pat)
return fnmatchcase(name, pat)
def filter(names, pat):
"""Return the subset of the list NAMES that match PAT"""
import os,posixpath
result=[]
pat=os.path.normcase(pat)
if not pat in _cache:
res = translate(pat)
_cache[pat] = re.compile(res)
match=_cache[pat].match
if os.path is posixpath:
# normcase on posix is NOP. Optimize it away from the loop.
for name in names:
if match(name):
result.append(name)
else:
for name in names:
if match(os.path.normcase(name)):
result.append(name)
return result
def fnmatchcase(name, pat):
"""Test whether FILENAME matches PATTERN, including case.
This is a version of fnmatch() which doesn't case-normalize
its arguments.
"""
if not pat in _cache:
res = translate(pat)
_cache[pat] = re.compile(res)
return _cache[pat].match(name) is not None
def translate(pat):
"""Translate a shell PATTERN to a regular expression.
There is no way to quote meta-characters.
"""
i, n = 0, len(pat)
res = ''
while i < n:
c = pat[i]
i = i+1
if c == '*':
res = res + '.*'
elif c == '?':
res = res + '.'
elif c == '[':
j = i
if j < n and pat[j] == '!':
j = j+1
if j < n and pat[j] == ']':
j = j+1
while j < n and pat[j] != ']':
j = j+1
if j >= n:
res = res + '\\['
else:
stuff = pat[i:j].replace('\\','\\\\')
i = j+1
if stuff[0] == '!':
stuff = '^' + stuff[1:]
elif stuff[0] == '^':
stuff = '\\' + stuff
res = '%s[%s]' % (res, stuff)
else:
res = res + re.escape(c)
return res + "$"