Re: Pythonic way to count sequences

[Serhiy Storchaka]

25.04.13 08:26, Chris Angelico написав(ла):

So you can count them up directly with a dictionary:

count = {}
for sequence_tuple in list_of_tuples:
     count[sequence_tuple] = count.get(sequence_tuple,0) + 1

Or alternatives:

count = {}
for sequence_tuple in list_of_tuples:
     if sequence_tuple] in count:
          count[sequence_tuple] += 1
     else:
          count[sequence_tuple] = 1

count = {}
for sequence_tuple in list_of_tuples:
     try:
          count[sequence_tuple] += 1
     except KeyError:
          count[sequence_tuple] = 1

import collections
count = collections.defaultdict(int)
for sequence_tuple in list_of_tuples:
     count[sequence_tuple] += 1

But of course collections.Counter is a preferable way now.


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