mdellavo · August 22, 2017 13:42
diff --git a/gistfile1.txt b/gistfile1.txt

 class GeneratorContextManager(object):
    """Helper for @contextmanager decorator."""

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

    def __enter__(self):
        try:
            return self.gen.next()
        except StopIteration:
            raise RuntimeError("generator didn't yield")

    def __exit__(self, type, value, traceback):
        if type is None:
            try:
                self.gen.next()
            except StopIteration:
                return
            else:
                raise RuntimeError("generator didn't stop")
        else:
            if value is None:
                # Need to force instantiation so we can reliably
                # tell if we get the same exception back
                value = type()
            try:
                self.gen.throw(type, value, traceback)
                raise RuntimeError("generator didn't stop after throw()")
            except StopIteration, exc:
                # Suppress the exception *unless* it's the same exception that
                # was passed to throw().  This prevents a StopIteration
                # raised inside the "with" statement from being suppressed
                return exc is not value
            except:
                # only re-raise if it's *not* the exception that was
                # passed to throw(), because __exit__() must not raise
                # an exception unless __exit__() itself failed.  But throw()
                # has to raise the exception to signal propagation, so this
                # fixes the impedance mismatch between the throw() protocol
                # and the __exit__() protocol.
                #
                if sys.exc_info()[1] is not value:
                    raise


 def contextmanager(func):
    """@contextmanager decorator.

    Typical usage:

        @contextmanager
        def some_generator(<arguments>):
            <setup>
            try:
                yield <value>
            finally:
                <cleanup>

    This makes this:

        with some_generator(<arguments>) as <variable>:
            <body>

    equivalent to this:

        <setup>
        try:
            <variable> = <value>
            <body>
        finally:
            <cleanup>

    """
    @wraps(func)
    def helper(*args, **kwds):
        return GeneratorContextManager(func(*args, **kwds))
    return helper

	class GeneratorContextManager(object):
	"""Helper for @contextmanager decorator."""

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

	def __enter__(self):
	try:
	return self.gen.next()
	except StopIteration:
	raise RuntimeError("generator didn't yield")

	def __exit__(self, type, value, traceback):
	if type is None:
	try:
	self.gen.next()
	except StopIteration:
	return
	else:
	raise RuntimeError("generator didn't stop")
	else:
	if value is None:
	# Need to force instantiation so we can reliably
	# tell if we get the same exception back
	value = type()
	try:
	self.gen.throw(type, value, traceback)
	raise RuntimeError("generator didn't stop after throw()")
	except StopIteration, exc:
	# Suppress the exception unless it's the same exception that
	# was passed to throw(). This prevents a StopIteration
	# raised inside the "with" statement from being suppressed
	return exc is not value
	except:
	# only re-raise if it's not the exception that was
	# passed to throw(), because __exit__() must not raise
	# an exception unless __exit__() itself failed. But throw()
	# has to raise the exception to signal propagation, so this
	# fixes the impedance mismatch between the throw() protocol
	# and the __exit__() protocol.
	#
	if sys.exc_info()[1] is not value:
	raise


	def contextmanager(func):
	"""@contextmanager decorator.

	Typical usage:

	@contextmanager
	def some_generator(<arguments>):
	<setup>
	try:
	yield <value>
	finally:
	<cleanup>

	This makes this:

	with some_generator(<arguments>) as <variable>:
	<body>

	equivalent to this:

	<setup>
	try:
	<variable> = <value>
	<body>
	finally:
	<cleanup>

	"""
	@wraps(func)
	def helper(args, *kwds):
	return GeneratorContextManager(func(args, *kwds))
	return helper