When I try to get more than one aggregation for a DataFrame, I get a header with more than one row:
df = df.groupby(['user', 'cat1 'cat2'])
df = df.aggregate({
    'user': ['count'],
    'profit': [np.average, np.sum]
    })
Output:
user                                profit
                        count   average    sum
user    cat1    cat2            
123     A       85963   1       91.33    56.22
456     A       5639    1       67.32    52.11
789     B       68593   1       33.55    45.88
Exporting this to csv results in two or more header rows:
,user,cat1,cat2,user,profit,profit
,,,,count,average,sum
[...]
What am I doing wrong?
