Pandas Rename column names – How to

Using pandas and need to rename some columns? Here are a few different ways you can rename your columns in pandas, depending on how complicated your data frame is, whether the column names are part of your data frame or not and whether you need to rename the same column multiple times. The examples below all use Python 3, but the methods apply to any modern version of python (2 or 3).

How to rename column in Pandas Dataframe

Create a Sample DataFrame

import pandas as pd
 
# Create dataframe pandas with column names
 
df = pd.DataFrame({
                    'A': [86, 75, 64, 89, 92],
                    'B': [70, 87, 74, 51, 62],
                    'C': [85, 42, 62, 33, 66]
                  })
df

Finding the columns you want to rename

Now if you have a dataset with so many columns, it’s difficult to see them by printing the data frame. Instead, you can only print all columns like below.

Also Read: How to reset index Pandas

list(df)

Output

['A', 'B', 'C']

df.columns

Output

Index(['A', 'B', 'C'], dtype='object')

Renaming a single column

Now let’s say you just want to rename column “A” to “new_column“

df1 = df.rename(columns={'A': 'new_column'})
df1

Renaming multiple columns

If you want to change name of all columns of your dataframe. You can rename those columns with a dictionary where you can use dictionary keys and values to rename columns in a pandas DataFrame.

df2 = df.rename(columns={'A': 'newName1', 'B': 'newName2', 'C': 'newName3'})
df2

Rename columns with list

You can change all column names by assigning a list of new column names.

df.columns = ['list_col1', 'list_col2', 'list_col3']
df

Rename column by index position

You can rename a specific column by its index position.

df.rename(columns={ df.columns[1]: "new_col_index_1" }, inplace = True)
df

Adding a new column

Let’s try to add new column to our pandas dataframe.

import numpy as np

df_len = len(df)
new_val = pd.Series(np.random.randn(df_len))
df['new_col'] = new_val

df

Removing a column

Now if you want to delete any specific column from a pandas dataframe:

del df['new_col']
df

Conclusion

In this pandas rename column tutorial, we learned how to rename a column in pandas. We first renamed the column or header as new_column, then wrote code to rename all the column names with a certain prefix. Next, we used .rename() function in pandas to specify new column names for each row.

That’s it for today, if you have any questions or suggestions regarding this tutorial, feel free to mention those in the comment section below.

Anindya

Hi there, I’m Anindya Naskar, Data Science Engineer. I created this website to show you what I believe is the best possible way to get your start in the field of Data Science.