Pandas: subtract one column from another in a pivot table

Question

I would like to subtract one columns from another in a pivot table. \'diff\' shoud be the difference between 2017 and 2016

raw_data = {\'year\': [2016,2016,2017,         


        

Answer 1

You need remove [] in pivot_table for dont create MultiIndex in columns:

table=pd.pivot_table(df1,index='area',columns='year',values='age',aggfunc='mean')
print (table)
year  2016  2017
area            
A       10    50
B       12    52

table['diff']=table[2017]-table[2016]
print (table)
year  2016  2017  diff
area                  
A       10    50    40
B       12    52    40

Another possible solution is droplevel:

table=pd.pivot_table(df1,index=['area'],columns=['year'],values=['age'],aggfunc='mean')
table.columns = table.columns.droplevel(0)
print (table)
year  2016  2017
area            
A       10    50
B       12    52