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}]}

```