I want to use pickle in compile/exec, but it doesn't work for me. It only works when I use the global namespace. But I don't want to use global namespace, is there any way for that ? Thanks

>>> a = compile("def f():\n\t'hello'\nimport pickle\npickle.dumps(f)", "<stdin>", "exec")
>>> exec(a)            # works
>>> exec(a, {})        # fails  
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 4, in <module>
_pickle.PicklingError: Can't pickle <function f at 0x1050881e0>: it's not the same object as __main__.f
>>> exec(a, {'__name__': '__main__'})   # fails too
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 4, in <module>
_pickle.PicklingError: Can't pickle <function f at 0x1050882f0>: it's not the same object as __main__.f