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Comment by nbadg

16 days ago

Yes. The usual way to do this is to bind them as defaults to an argument, for example:

    def loop():
        for number in range(10):

            def func_w_closure(_num=number):
                return _num

            yield func_w_closure

This works because default arguments in python are evaluated exactly once, at function definition time. So it's a way of effectively copying the ``number`` out of the closure[1] and into the function definition.

[1] side note, closures in python are always late-binding, which is what causes the behavior in OP

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nbadg

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amluto  16 days ago

I’ve never thought that leaking this type of implementation detail into the return value (and return type!) was a nice solution. I like the double closure better, and one can shorten it a bit with a lambda.

For those who prefer a functional style, functools.partial can also solve this problem.

(I use Python, and I like a lot of things about Python, but I don’t like its scoping rules at all, nor do I like the way that Python’s closures work. I would use a double lambda.)