Question

I know that it is not safe to modify the list during an iterative looping. However, suppose I have a list of strings, and I want to strip the strings themselves. Does replacement of mutable values count as modification?

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_{See Why doesn't modifying the iteration variable affect subsequent iterations? for a related problem: assigning to the iteration variable does not modify the underlying sequence, and also does not impact future iteration.}

Answer 1

It’s considered poor form. Use a list comprehension instead, with slice assignment if you need to retain existing references to the list.

a = [1, 3, 5]
b = a
a[:] = [x + 2 for x in a]
print(b)