I assume OP refers to the cases where "while" is used to re-implement existing operations... imagine finding code like this:

     i = 0
     while i != len(todo):
         process(todo[i])
         i = i + 1

sure, there may be a good reason to implement things this way (maybe "todo" grows during iteration?), but maybe not, and then the loop should be instead simplified to:

     for value in todo:
         process(value)

(as an aside, this is exactly the case where the comments are required: "# not using for loop because todo might grow" will make it clear it's an intentional decision and not hallucination or something written from ignorance)