45 lines
1.4 KiB
Python
45 lines
1.4 KiB
Python
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"""Additional regular expression utilities, to make it easier to sync up
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with Java regular expression code.
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>>> import re
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>>> from .re_util import fullmatch
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>>> from .util import u
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>>> string = 'abcd'
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>>> r1 = re.compile('abcd')
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>>> r2 = re.compile('bc')
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>>> r3 = re.compile('abc')
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>>> fullmatch(r1, string) # doctest: +ELLIPSIS
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<...Match object...>
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>>> fullmatch(r2, string)
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>>> fullmatch(r3, string)
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>>> r = re.compile(r'\\d{8}|\\d{10,11}')
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>>> m = fullmatch(r, '1234567890')
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>>> m.end()
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10
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>>> r = re.compile(u(r'[+\uff0b\\d]'), re.UNICODE)
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>>> m = fullmatch(r, u('\uff10'))
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>>> m.end()
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1
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"""
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import re
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def fullmatch(pattern, string, flags=0):
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"""Try to apply the pattern at the start of the string, returning a match
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object if the whole string matches, or None if no match was found."""
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# Build a version of the pattern with a non-capturing group around it.
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# This is needed to get m.end() to correctly report the size of the
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# matched expression (as per the final doctest above).
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grouped_pattern = re.compile("^(?:%s)$" % pattern.pattern, pattern.flags)
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m = grouped_pattern.match(string)
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if m and m.end() < len(string):
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# Incomplete match (which should never happen because of the $ at the
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# end of the regexp), treat as failure.
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m = None # pragma no cover
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return m
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if __name__ == '__main__': # pragma no cover
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import doctest
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doctest.testmod()
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