gistfile1.txt

import functools


def contextmanager(function):
    @functools.wraps(function)
    def contextmanager_impl(*args, **kwargs):
        class contextmanager_impl_(object):
            def __init__(self):
                self.gen = function(*args, **kwargs)
                self.it = None

            def __enter__(self):
                self.it = iter(self.gen)
                return next(self.it)

            def __exit__(self, exception_type, exception_value, traceback):
                try:
                    if exception_value is not None:
                        self.it.throw(exception_value)
                    else:
                        next(self.it)
                except StopIteration:
                    pass
                return True
        return contextmanager_impl_()
    return contextmanager_impl