class Dict(dict):
    def __getitem__(self, key):
        if key == 's':
            return 'got s'
        return dict.__getitem__(self, key)

dct = Dict()
dct['the_dict'] = dct
print 0, id(dct)

source = """if 1:
    print '1', id(globals()), globals() is the_dict
    print ' ', globals()['s']
    print ' ', s
    def f():
        print '2', id(globals()), globals() is the_dict
        print ' ', globals()['s']
        print ' ', s
        print '3'
    f()"""

exec(source, dct)