Map function for nesting with statements

map_with.py

from contextlib import contextmanager
from copy import copy

@contextmanager
def map_with(funcs, args, init=True):

    if init:
        funcs, args = copy(funcs), copy(args)

    if len(funcs) == 0:
        yield []

    else:
        func, arg = funcs.pop(), args.pop()
        with func(arg) as f:
            with map_with(funcs, args, False) as out:
                yield out + [f]

@contextmanager
def func(val):

    print 'entering {}'.format(val)
    yield val
    print 'exiting {}'.format(val)

if __name__ == '__main__':

    funcs = [func] * 10
    args = range(10)
    
    with map_with(funcs, args) as out:
        print out