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I'm new here and a newbie in Python. I'd like to ask a question about calculating frequency for multiple combination of variables in Python.

I have a list of a lists that looks like this for example:

[[A,A,A],[A,B,C],[A,A,A],[A,B,B],[A,B,C]]

And I want python to count the frequency for all combination in that list, and the result will look like this:

[[A,A,A,2],[A,B,C,2],[A,B,B,1]]

Is there any possible way in Python to do that, or is there any python module that supports something similar to that? I've found a function in Arcpy module that I think similar to what I want to do here but I don't own any ArcGIS license or software so I can't get access to use that function.

Bhavik Ambani
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user3268302
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  • `collections.Counter` can count tuples. Just count tuples. – roippi Feb 04 '14 at 03:37
  • Maybe I have to learn more about differences between tuple and list, not having a good understanding about those two file types for now. Thank you roippi. – user3268302 Feb 04 '14 at 06:45

1 Answers1

3

Without using additional libraries:

listOfItems = [['A','A','A'],['A','B','C'],['A','A','A'],['A','B','B'],['A','B','C']]
setOfItems = []
newListOfItems = []
for item in listOfItems:
    if item in setOfItems:
        continue
    setOfItems.append(item)
    temp = list(item)
    occurence = listOfItems.count(item)
    temp.append(occurence)
    newListOfItems.append(temp)

print newListOfItems

Result is:

   >>> print newListOfItems
   [['A', 'A', 'A', 2], ['A', 'B', 'C', 2], ['A', 'B', 'B', 1]]
Chandan
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