Question

Sorry if this is too simple a question, but is there a sumif function in python that will sum by identifier and category? So in this case, I would like to have a function sumif which takes as arguments the identifier and the year and sums the amount. For example sumif('105','2006') should return 1200.

data = {'105':[{'2005': 500}, {'2005', 13000}, {'2006', 100}, {'2006', 200}, {'2006', 900}], '256': [{'2005', 5000}, {'2005', 800}]}

Answer 1

>>> from collections import Counter
>>> data = {'105':[{'2005': 500}, {'2005': 13000}, {'2006': 100}, {'2006': 200}, {'2006': 900}], '256': [{'2005': 5000}, {'2005': 800}]}

>>> sum(map(Counter, data['105']), Counter())['2006']
1200

Therefore the definition of sumif would be:

sumif = lambda x, y: sum(map(Counter, data[x]), Counter())[y]