Pandas: How to Rename Columns with Dictionary

You can use the following basic syntax to rename columns with a dictionary in pandas:

#define dictionary
some_dict = {'old_col1': 'new_col1',
             'old_col2': 'new_col2',
             'old_col3': 'new_col3'}
 
#rename columns in DataFrame using dictionary
df.rename(columns=some_dict, inplace=True)

Note: We must specify inplace=True to modify the column names of the original DataFrame.

The following example shows how to use this syntax in practice.

Example: Rename Columns in Pandas with Dictionary

Suppose we have the following pandas DataFrame:

import pandas as pd

#create DataFrame
df = pd.DataFrame({'rebounds': [10, 14, 14, 13, 13, 12, 10, 7],
                    'points': [30, 22, 19, 14, 14, 11, 20, 28],
                    'assists': [5, 6, 6, 5, 8, 7, 7, 9]})

#view DataFrame
print(df)

   rebounds  points  assists
0        10      30        5
1        14      22        6
2        14      19        6
3        13      14        5
4        13      14        8
5        12      11        7
6        10      20        7
7         7      28        9

We can use the following syntax to rename each of the columns in the DataFrame using a dictionary:

#define dictionary with new column names
some_dict = {'rebounds': 'rebs',
             'points': 'pts',
             'assists': 'ast'}
 
#rename columns in DataFrame using dictionary
df.rename(columns=some_dict, inplace=True)

#view updated DataFrame
print(df)

   rebs  pts  ast
0    10   30    5
1    14   22    6
2    14   19    6
3    13   14    5
4    13   14    8
5    12   11    7
6    10   20    7
7     7   28    9

Notice that each of the columns have been renamed based on the values we specified in the dictionary.

It’s worth noting that you don’t have to rename every single column using a dictionary.

For example, we could create a dictionary to only rename the points and assists columns in the DataFrame:

#define dictionary with new column names for points and assists only
some_dict = {'points': 'pts',
             'assists': 'ast'}
 
#rename columns in DataFrame using dictionary
df.rename(columns=some_dict, inplace=True)

#view updated DataFrame
print(df)

   rebounds  pts  ast
0        10   30    5
1        14   22    6
2        14   19    6
3        13   14    5
4        13   14    8
5        12   11    7
6        10   20    7
7         7   28    9

Only the points and assists columns were renamed.

Since the rebounds column was not included in the dictionary, it was not renamed in the DataFrame.