calculate quarters from months

Question

I have a data frame with a number of columns by month

c1 c2 yyyy-01 yyyy-02 yyyy-03 yyyy-04 yyyy-05 yyyy-06 ...
 a  A     1      1       3      2       2                


        

Answer 1

1. Use pd.to_datetime() and to_period() functions to create a group variable of quarters for each year;
2. You can pass an axis parameter to the groupby() function to group your data frame by columns, in this case the column index.

so, you can try:

df.set_index(['c1', 'c2'], inplace=True)
df

df.groupby(pd.to_datetime(df.columns).to_period("Q"), axis=1).sum().reset_index()