Pandas group by and sum two columns

Question

Beginner question. This seems like it should be a straightforward operation, but I can\'t figure it out from reading the docs.

I have a df with this structure:

Answer 1

A variation on the .agg() function; provides the ability to (1) persist type DataFrame, (2) apply averages, counts, summations, etc. and (3) enables groupby on multiple columns while maintaining legibility.

df.groupby(['att1', 'att2']).agg({'att1': "count", 'att3': "sum",'att4': 'mean'})

using your values...

df.groupby(['integer_id']).agg({'int_field_1': "sum", 'int_field_2': "sum" })

Answer 2

You just need to call sum on a groupby object:

df.groupby('integer_id').sum()

See the docs for further examples

Answer 3

You can do it

data.groupby(by=['account_ID'])['purchases'].sum()