Indexes of most common value in array of integers. Without importing any library

most_commons.py

"""
Indexes of most common value in array of integers.
Without importing any library.
@author: avalanchy
Python 2.7 
"""

# random 1 million 
from random import randint
array = [randint(1, 100) for _ in xrange(1, 10**6)]

most_common = max(set(array), key=array.count)
indexes = [n for n, val in enumerate(array) if val == most_common]