python get list id from the value code example

Example: how to place an id to every element in list in python

from collections import defaultdict

omg = ['a', 'b', 'c', 'a', 'b', 1]
d = defaultdict(lambda: len(d))  # late binding allows d not to be defined yet
omg_id = [d[x] for x in omg]
# [0, 1, 2, 0, 1, 3]