loop through values from a list of dictionaries in Python

Question

Given a list of dictionaries in python like this:

dict_list = [
{'a' : 1, 'b' : 2},
{'c' : 2, 'd' : 3},
{'x' : 4, 'y' : 5, 'z': 0}
]

What is the best to loop through all the values while emulating the obvious:

for i in dict_list:
    for x in i.values():
        print x

But ideally avoiding the nested for loops. I'm sure there must be a better way but I can't find it.

http://stackoverflow.com/questions/3294889/iterating-over-dictionaries-for-loops-in-python — devnull, May 13 '14 at 08:54
http://stackoverflow.com/questions/3458285/loop-through-list-of-dictionaries — devnull, May 13 '14 at 08:54
@thefourtheye I want a cleaner way of doing what I show in my second code block — nettux, May 13 '14 at 09:01
I'd like some explanation of the downvotes. This is not a duplicate post to the best of my knowledge, it's a reasonable, clear question and I've got a satisfactory answer. — nettux, May 13 '14 at 09:05
@Matthias it looks simple but I'd rather not have a loop inside a loop if I can help it. — nettux, May 13 '14 at 09:06
@nettux443 sshashank's answer does have a loop inside a loop. It is just not nested. — Davidmh, May 13 '14 at 09:19
@Davidmh **read my question**. Last line: "But ideally avoiding the nested ````for```` loops". sshashank124's answer is really a ````for```` **followed by** a ````for```` loop as the entire list is generated before I start iterating over it. — nettux, May 13 '14 at 09:23

sshashank124 · Accepted Answer · 2014-05-13T09:08:15.477

2

To loop through all the values, use itertools.chain.from_iterable

from itertools import chain

dict_list = [
{'a' : 1, 'b' : 2},
{'c' : 2, 'd' : 3},
{'x' : 4, 'y' : 5, 'z': 0}
]

for item in chain.from_iterable(i.values() for i in dict_list):
    print item

Outputs:

edited May 13 '14 at 09:08

answered May 13 '14 at 08:55

sshashank124

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@thefourtheye, The OP has updated the question which makes it clearer – sshashank124 May 13 '14 at 08:57
`list` spoils everything. It is not needed. – thefourtheye May 13 '14 at 09:07
I would have settled with a generator expression, rather than chaining – thefourtheye May 13 '14 at 09:08
@thefourtheye, I have removed the list. – sshashank124 May 13 '14 at 09:08

loop through values from a list of dictionaries in Python

1 Answers1