Python 2to3 Warning You should use ‘operator.mul(None)’ here. What does this mean?

I’m using a 2to3 conversion script. The only warning I got was:

RefactoringTool: Line 716: You should use 'operator.mul(None)' here.

Line 716 of the original script is:

classes = repeat(None)

I don’t know where I should use operator.mul(None). repeat() ( link to docs ) The referenced documentation shows that I can pass None without any problems. So, what should I do?

2to3 is confused about which repeat you are referring to. It assumes that you are using operator.repeat:: in Python 2

Help on built-in function repeat in module operator:

repeat(...)
    repeat(a, b) -- Return a * b, where a is a sequence, and b is an integer.

Instead of itertools.repeat. Honestly, it’s not a good guess because operator.repeat has two arguments, but that’s what it’s guessing. You can see the transformations listed in the docs

You can use fully qualified itertools.repeat or ignore it to avoid warnings.