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

Sometimes matplotlib requires range(len(y)), e.g., while y=array([1,2,5,6]), plot(y) works fine, scatter(y) does not. One has to write scatter(range(len(y)),y). (Personally, I think this is a bug in scatter; plot and its friends scatter and stem should use the same calling sequences as much as possible.)