Comments on: Count the duplicates in a Python List http://bigbadcode.com/2007/04/04/count-the-duplicates-in-a-python-list/ this blog is retired. I'm leaving it up as a reference Tue, 12 Apr 2011 08:42:56 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: Diego Castro http://bigbadcode.com/2007/04/04/count-the-duplicates-in-a-python-list/#comment-5574 Diego Castro Fri, 17 Dec 2010 20:02:51 +0000 http://bigbadcode.com/2007/04/04/count-the-duplicates-in-a-python-list/#comment-5574 Thanks man, Just a correction ... the Set on the seco0nd line should be set (lowercase) (at least changing the case made it work here) Thanks man,
Just a correction … the Set on the seco0nd line should be set (lowercase)

(at least changing the case made it work here)

]]> By: Stefan http://bigbadcode.com/2007/04/04/count-the-duplicates-in-a-python-list/#comment-5537 Stefan Thu, 04 Jun 2009 11:01:13 +0000 http://bigbadcode.com/2007/04/04/count-the-duplicates-in-a-python-list/#comment-5537 Thanks, this was a useful snippet! Thanks, this was a useful snippet!

]]> By: sfrank http://bigbadcode.com/2007/04/04/count-the-duplicates-in-a-python-list/#comment-5485 sfrank Fri, 17 Oct 2008 11:16:06 +0000 http://bigbadcode.com/2007/04/04/count-the-duplicates-in-a-python-list/#comment-5485 Thanks, this was what I was looking for, couldn't see how to do it! Thanks, this was what I was looking for, couldn’t see how to do it!

]]> By: Ian Eloff http://bigbadcode.com/2007/04/04/count-the-duplicates-in-a-python-list/#comment-5476 Ian Eloff Sun, 21 Sep 2008 19:05:26 +0000 http://bigbadcode.com/2007/04/04/count-the-duplicates-in-a-python-list/#comment-5476 Another way to do this is: >>> from collections import defaultdict >>> lst = ['I1','I2','I1','I3','I4','I4','I7','I7','I7','I7','I7'] >>> def count_dups(l): ... tally = defaultdict(int) ... for x in l: ... tally[x] += 1 ... return tally.items() ... >>> count_dups(lst) [('I1', 2), ('I3', 1), ('I2', 1), ('I4', 2), ('I7', 5)] Another way to do this is:

>>> from collections import defaultdict
>>> lst = ['I1','I2','I1','I3','I4','I4','I7','I7','I7','I7','I7']
>>> def count_dups(l):
… tally = defaultdict(int)
… for x in l:
… tally[x] += 1
… return tally.items()
…
>>> count_dups(lst)
[('I1', 2), ('I3', 1), ('I2', 1), ('I4', 2), ('I7', 5)]

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