argmax

iteration_utilities.argmax(iterable, /, key=None, default=None)

Find index of the maximum.

Parameters:

iterable : iterable

The iterable for which to calculate the index of the maximum.

Note

Instead of one iterable it is also possible to pass the values (at least 2) as positional arguments.

key : callable, optional

If not given then compare the values, otherwise compare key(item).

default : int, optional

If not given raise ValueError if the iterable is empty otherwise return default

Returns:

argmax : int

The index of the maximum or default if the iterable was empty.

Examples

This is equivalent (but faster) than max(enumerate(iterable), key=operator.itemgetter(1))[0]:

>>> from iteration_utilities import argmax
>>> argmax(3,2,1,2,3)
0

It allows a key function:

>>> argmax([0, -3, 3, 0], key=abs)
1

And a default:

>>> argmax([], default=10)
10