GroupBy Two & Three Group Columns of pandas DataFrame in Python (2 Examples)

import pandas as pd                                       # Load pandas library

import pandas as pd # Load pandas library

my_df = pd.DataFrame({'A':range(19, 28),                  # Constructing a pandas DataFrame
                      'B':[6, 7, 3, 9, 1, 3, 8, 8, 9],
                      'C':range(20, 11, - 1),
                      'GRP_a':['gr1', 'gr1', 'gr2', 'gr3', 'gr1', 'gr2', 'gr2', 'gr3', 'gr3'],
                      'GRP_b':['x', 'x', 'x', 'x', 'y', 'y', 'y', 'y', 'y'],
                      'GRP_c':['a', 'b', 'c', 'c', 'a', 'b', 'b', 'a', 'a']})
print(my_df)
#     A  B   C GRP_a GRP_b GRP_c
# 0  19  6  20   gr1     x     a
# 1  20  7  19   gr1     x     b
# 2  21  3  18   gr2     x     c
# 3  22  9  17   gr3     x     c
# 4  23  1  16   gr1     y     a
# 5  24  3  15   gr2     y     b
# 6  25  8  14   gr2     y     b
# 7  26  8  13   gr3     y     a
# 8  27  9  12   gr3     y     a

my_df = pd.DataFrame({'A':range(19, 28), # Constructing a pandas DataFrame 'B':[6, 7, 3, 9, 1, 3, 8, 8, 9], 'C':range(20, 11, - 1), 'GRP_a':['gr1', 'gr1', 'gr2', 'gr3', 'gr1', 'gr2', 'gr2', 'gr3', 'gr3'], 'GRP_b':['x', 'x', 'x', 'x', 'y', 'y', 'y', 'y', 'y'], 'GRP_c':['a', 'b', 'c', 'c', 'a', 'b', 'b', 'a', 'a']}) print(my_df) # A B C GRP_a GRP_b GRP_c # 0 19 6 20 gr1 x a # 1 20 7 19 gr1 x b # 2 21 3 18 gr2 x c # 3 22 9 17 gr3 x c # 4 23 1 16 gr1 y a # 5 24 3 15 gr2 y b # 6 25 8 14 gr2 y b # 7 26 8 13 gr3 y a # 8 27 9 12 gr3 y a

print(my_df.groupby(['GRP_a', 'GRP_b']).sum())            # Computing the column sum by two groups
#               A   B   C
# GRP_a GRP_b            
# gr1   x      39  13  39
#       y      23   1  16
# gr2   x      21   3  18
#       y      49  11  29
# gr3   x      22   9  17
#       y      53  17  25

print(my_df.groupby(['GRP_a', 'GRP_b']).sum()) # Computing the column sum by two groups # A B C # GRP_a GRP_b # gr1 x 39 13 39 # y 23 1 16 # gr2 x 21 3 18 # y 49 11 29 # gr3 x 22 9 17 # y 53 17 25

print(my_df.groupby(['GRP_a', 'GRP_b', 'GRP_c']).mean())  # Computing the column sum by multiple groups
#                       A    B     C
# GRP_a GRP_b GRP_c                 
# gr1   x     a      19.0  6.0  20.0
#             b      20.0  7.0  19.0
#       y     a      23.0  1.0  16.0
# gr2   x     c      21.0  3.0  18.0
#       y     b      24.5  5.5  14.5
# gr3   x     c      22.0  9.0  17.0
#       y     a      26.5  8.5  12.5

print(my_df.groupby(['GRP_a', 'GRP_b', 'GRP_c']).mean()) # Computing the column sum by multiple groups # A B C # GRP_a GRP_b GRP_c # gr1 x a 19.0 6.0 20.0 # b 20.0 7.0 19.0 # y a 23.0 1.0 16.0 # gr2 x c 21.0 3.0 18.0 # y b 24.5 5.5 14.5 # gr3 x c 22.0 9.0 17.0 # y a 26.5 8.5 12.5