re の MatchObject を with のコンテキストにする

matchcontext.py

# coding: utf-8

class MatchContext(object):
    """
    >>> import re
    >>> with MatchContext(re.match(r'(.)', 'a')) as context:
    ...     print context.groups()
    ('a',)
    >>> import re
    >>> with MatchContext(re.match(r'(.)', '')) as context:
    ...     print context.groups()
    >>> # context.groups should raise error but suppressed by __exit__.
    """

    def __init__(self, match):
        self.match = match

    def __enter__(self):
        return self.match

    def __exit__(self, exc_type, exc_value, traceback):
        return True


if __name__=='__main__':
    from doctest import testmod
    testmod()