mirror of https://github.com/python/cpython
merge with 3.2
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9758fcfb87
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@ -1093,28 +1093,6 @@ The equivalent regular expression would be ::
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(\S+) - (\d+) errors, (\d+) warnings
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Avoiding recursion
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^^^^^^^^^^^^^^^^^^
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If you create regular expressions that require the engine to perform a lot of
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recursion, you may encounter a :exc:`RuntimeError` exception with the message
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``maximum recursion limit exceeded``. For example, ::
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>>> s = 'Begin ' + 1000*'a very long string ' + 'end'
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>>> re.match('Begin (\w| )*? end', s).end()
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Traceback (most recent call last):
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File "<stdin>", line 1, in ?
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File "/usr/local/lib/python3.2/re.py", line 132, in match
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return _compile(pattern, flags).match(string)
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RuntimeError: maximum recursion limit exceeded
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You can often restructure your regular expression to avoid recursion.
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Simple uses of the ``*?`` pattern are special-cased to avoid recursion. Thus,
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the above regular expression can avoid recursion by being recast as ``Begin
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[a-zA-Z0-9_ ]*?end``. As a further benefit, such regular expressions will run
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faster than their recursive equivalents.
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.. _search-vs-match:
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search() vs. match()
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@ -1161,7 +1139,7 @@ creates a phonebook.
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First, here is the input. Normally it may come from a file, here we are using
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triple-quoted string syntax:
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>>> input = """Ross McFluff: 834.345.1254 155 Elm Street
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>>> text = """Ross McFluff: 834.345.1254 155 Elm Street
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...
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... Ronald Heathmore: 892.345.3428 436 Finley Avenue
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... Frank Burger: 925.541.7625 662 South Dogwood Way
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@ -1175,7 +1153,7 @@ into a list with each nonempty line having its own entry:
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.. doctest::
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:options: +NORMALIZE_WHITESPACE
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>>> entries = re.split("\n+", input)
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>>> entries = re.split("\n+", text)
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>>> entries
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['Ross McFluff: 834.345.1254 155 Elm Street',
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'Ronald Heathmore: 892.345.3428 436 Finley Avenue',
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