#!/usr/bin/env python

__author__ = "bt3"

from collections import defaultdict

def  defaultdict_example():
    ''' show some examples for defaultdicts '''
    pairs = {('a', 1), ('b',2), ('c',3)}

    d1 = {}
    for key, value in pairs:
        if key not in d1:
            d1[key] = []
        d1[key].append(value)
    print(d1)

    d2 = defaultdict(list)
    for key, value in pairs:
        d2[key].append(value)
    print(d2)


if __name__ == '__main__':
    defaultdict_example()