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Rebind (Python recipe) by Neal Becker
ActiveState Code (http://code.activestate.com/recipes/546510/)

Temporarily rebind an attribute using contextmanager

Python, 17 lines
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from __future__ import with_statement
from contextlib import contextmanager


@contextmanager
def redirect(object_, attr, value):
    orig = getattr(object_, attr)
    setattr(object_, attr, value)
    yield
    setattr(object_, attr, orig)

if __name__ == "__main__":
    import sys
    with redirect(sys, 'stdout', open('stdout', 'w')):
        print "hello"

    print "we're back"

Initially, I wanted to redirect stdout in a block. Later I realized this this is just an example of a more general useful pattern of rebinding an attribute of an object.

Tags: shortcuts