Is it possible to access enclosing context manager?

Question

There are essentially three ways to use the with statement:

Use an existing context manager:

with manager:
    pass

Create a contex

Answer 1

If the context manager is a class and only ever has a single instance, then you could find it on the heap:

import gc

class ConMan(object):
    def __init__(self, name):
        self.name = name

    def __enter__(self):
        print "enter %s" % self.name

    def found(self):
        print "You found %s!" % self.name

    def __exit__(self, *args):
        print "exit %s" % self.name


def find_single(typ):
    single = None
    for obj in gc.get_objects():
        if isinstance(obj, typ):
            if single is not None:
                raise ValueError("Found more than one")
            single = obj
    return single



def foo():
    conman = find_single(ConMan)
    conman.found()

with ConMan('the-context-manager'):
    foo()

(Disclaimer: Don't do this)