Only index needed: enumerate or (x)range?

Question

If I want to use only the index within a loop, should I better use the range/xrange function in combination with len()

a = [1,2,3]         


        

Answer 1

Using xrange with len is quite a common use case, so yes, you can use it if you only need to access values by index.

But if you prefer to use enumerate for some reason, you can use underscore (_), it's just a frequently seen notation that show you won't use the variable in some meaningful way:

for i, _ in enumerate(a):
    print i

There's also a pitfall that may happen using underscore (_). It's also common to name 'translating' functions as _ in i18n libraries and systems, so beware to use it with gettext or some other library of such kind (thnks to @lazyr).