Pandas: sum up multiple columns into one column without last column

Question

If I have a dataframe similar to this one

Apples   Bananas   Grapes   Kiwis
2        3         nan      1
1        3         7        nan
nan      nan       2            


        

Answer 1

Using df['Fruit Total']= df.iloc[:, -4:-1].sum(axis=1) over your original df won't add the last column ('Kiwis'), you should use df.iloc[:, -4:] instead to select all columns:

print(df)
   Apples  Bananas  Grapes  Kiwis
0     2.0      3.0     NaN    1.0
1     1.0      3.0     7.0    NaN
2     NaN      NaN     2.0    3.0

df['Fruit Total']=df.iloc[:,-4:].sum(axis=1)

print(df)
   Apples  Bananas  Grapes  Kiwis  Fruit Total
0     2.0      3.0     NaN    1.0          6.0
1     1.0      3.0     7.0    NaN         11.0
2     NaN      NaN     2.0    3.0          5.0