Is there a need for range(len(a))?

Question

One frequently finds expressions of this type in python questions on SO. Either for just accessing all items of the iterable

for i in range(len(a)):
    prin         


        

Answer 1

If you need to work with indices of a sequence, then yes - you use it... eg for the equivalent of numpy.argsort...:

>>> a = [6, 3, 1, 2, 5, 4]
>>> sorted(range(len(a)), key=a.__getitem__)
[2, 3, 1, 5, 4, 0]