Python serialize lexical closures?

Question

Is there a way to serialize a lexical closure in Python using the standard library? pickle and marshal appear not to work with lexical closures. I don\'t really care about

Answer 1

If you simply use a class with a __call__ method to begin with, it should all work smoothly with pickle.

class foo(object):
    def __init__(self, bar, baz):
        self.baz = baz
    def __call__(self,waldo):
        return self.baz * waldo

On the other hand, a hack which converted a closure into an instance of a new class created at runtime would not work, because of the way pickle deals with classes and instances. pickle doesn't store classes; only a module name and class name. When reading back an instance or class it tries to import the module and find the required class in it. If you used a class created on-the-fly, you're out of luck.