Is there a simple way to find the list index to the max value?

[Arnaud Delobelle]

"W. eWatson" <wolftracks at invalid.com> writes:

> See Subject. a = [1,4,9,3]. Find max, 9, then index to it, 2.

Here are a few ways.

>>> a = [1,4,9,3]
>>> max_index = max(xrange(len(a)), key=a.__getitem__)
>>> max_index
2
>>> # Or:
... max_index = max((n, i) for i, n in enumerate(a))[1]
>>> max_index
2
>>> # Or:
... from itertools import *
>>> max_index = max(izip(a, count()))[1]
>>> max_index
2

-- 
Arnaud