You can use the following methods to add a suffix to column names in a pandas DataFrame:

Method 1: Add Suffix to All Column Names

df = df.add_suffix('_my_suffix')

Method 2: Add Suffix to Specific Column Names

#specify columns to add suffix to
cols = ['col1', 'col3']

#add suffix to specific columns
df = df.rename(columns={c: c+'_my_suffix' for c in df.columnsif c in cols})

The following examples show how to use each of these methods with the following pandas DataFrame:

import pandas as pd
#create DataFrame
df = pd.DataFrame({'points': [25, 12, 15, 14, 19, 23],
                   'assists': [5, 7, 7, 9, 12, 9],
                   'rebounds': [11, 8, 10, 6, 6, 5],
                   'blocks': [6, 6, 3, 2, 7, 9]})

#view DataFrame
print(df)

   points  assists  rebounds  blocks
0      25        5        11       6
1      12        7         8       6
2      15        7        10       3
3      14        9         6       2
4      19       12         6       7
5      23        9         5       9

Method 1: Add Suffix to All Column Names

The following code shows how to add the suffix ‘_total’ to all column names:

#add '_total' as suffix to each column name
df = df.add_suffix('_total')

#view updated DataFrame
print(df)

   points_total  assists_total  rebounds_total  blocks_total
0            25              5              11             6
1            12              7               8             6
2            15              7              10             3
3            14              9               6             2
4            19             12               6             7
5            23              9               5             9

Notice that the suffix ‘_total’ has been added to all column names.

Note: To add a prefix to column names, simply use add_prefix instead.

Method 2: Add Suffix to Specific Column Names

The following code shows how to add the suffix ‘_total’ to only the points and assists columns:

#specify columns to add suffix to
cols = ['points', 'assists']

#add _'total' as suffix to specific columns
df = df.rename(columns={c: c+'_total' for c in df.columns if c in cols})

#view updated DataFrame
print(df)

   points_total  assists_total  rebounds  blocks
0            25              5        11       6
1            12              7         8       6
2            15              7        10       3
3            14              9         6       2
4            19             12         6       7
5            23              9         5       9

Notice that the suffix ‘_total’ has only been added to the points and assists columns.