Removing duplicate keys from python dictionary but summing the values

Question

I have a dictionary in python

d = {tags[0]: value, tags[1]: value, tags[2]: value, tags[3]: value, tags[4]: value}

imagine that this dict i

Answer 1

tps = [('cat',5),('dog',9),('cat',4),('parrot',6),('cat',6)]

from collections import defaultdict

dicto = defaultdict(int)

for k,v in tps:
    dicto[k] += v

Result:

>>> dicto
defaultdict(<type 'int'>, {'dog': 9, 'parrot': 6, 'cat': 15})

Answer 2

If I understand correctly your question that you want to get rid of duplicate key data, use update function of dictionary while creating the dictionary. it will overwrite the data if the key is duplicate.

tps = [('cat',5),('dog',9),('cat',4),('parrot',6),('cat',6)]
result = {}
for k, v in tps:
    result.update({k:v})
for k in result:
    print "%s: %s" % (k, result[k]) 

Output will look like: dog: 9 parrot: 6 cat: 6