Change Column Names in Pandas Dataframe

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This article will discuss how to change column names in a Pandas Dataframe in Python.

Table Of Contents

A DataFrame is a data structure that stores the data in rows and columns. We can create a DataFrame using pandas.DataFrame() method. Let’s discuss the techniques to rename columns in a Pandas Dataframe.

Change Column Names in Dataframe using rename() method

In Pandas, the Dataframe provides a function rename(), which accepts a dictionary as an argument. This dictionary contains the mapping of old column names with the new column names. It replaces the old column names with the new ones in the Dataframe.

Syntax is as follows:

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df.rename(columns,inplace=True)

where,

  • df is the input dataframe
  • columns parameter take a dictionary of old and new column names.
    • {‘old_column_name’:’new_column_name’,……………,’old_column_name’:’new_column_name’}
  • inplace is used to make the changes in current Dataframe

Note: We can rename single or multiple columns at a time.

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Let’s see the examples.

Before that We create the DataFrame. Here, we are going to create the DataFrame named data with 4 rows and 4 columns.

import pandas as pd

# Create the dataframe with four columns
df = pd.DataFrame({'id':[7058,7069,7060,7061],
                   'name':['sravan','bobby','ojaswi','deepu'],
                   'age':[21,23,22,21],
                   'subjects':['linux','html/css','node-js','php-mysql']})

# Display The Dataframe
print(df)

Output:

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     id    name  age   subjects
0  7058  sravan   21      linux
1  7069   bobby   23   html/css
2  7060  ojaswi   22    node-js
3  7061   deepu   21  php-mysql

Rename single column

Here we are going to display the dataframe by renaming the single column for all the columns.

# Rename id column with student_id
df.rename(columns={'id':'student_id'}, inplace=True)

# Rename name column with student_name
df.rename(columns={'name':'student_name'}, inplace=True)

# Rename age column with student_age
df.rename(columns={'age':'student_age'}, inplace=True)

# Rename subjects column with Programming
df.rename(columns={'subjects':'Programming'}, inplace=True)

# Display the Dataframe
print(df)

Output:

   student_id student_name  student_age Programming
0        7058       sravan           21       linux
1        7069        bobby           23    html/css
2        7060       ojaswi           22     node-js
3        7061        deepu           21   php-mysql

Here we renamed id column with student_id, name column with student_name, age column with student_age, subjects column with Programming.

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Rename multiple columns

Here we are going to display the dataframe by renaming the multiple columns at a time.

# Rename id column with student_id
# Rename name  column with student_name
# Rename age  column with student_age
# Rename subjects  column with Programming
df.rename(columns={ 'id':'student_id',
                    'name':'student_name',
                    'age':'student_age',
                    'subjects':'Programming'},
                    inplace=True)

# Display the Dataframe
print(df)

Output:

   student_id student_name  student_age Programming
0        7058       sravan           21       linux
1        7069        bobby           23    html/css
2        7060       ojaswi           22     node-js
3        7061        deepu           21   php-mysql

Here we renamed,

  • id column with student_id
  • name column with student_name
  • age column with student_age
  • subjects column with Programming.

Change Column Names in Dataframe using columns attribute with list

In this method, we are using a list that contains a new column names and then we assign this list to dataframe’s columns attribute. It will replace the old column names with new one,

Syntax is as follows:

dataframe.columns=['new_column1',.........,'new_column n']

Here we are going to rename columns using a list of column names

import pandas as pd

# Create the dataframe with four columns
df = pd.DataFrame({'id':[7058,7069,7060,7061],
                   'name':['sravan','bobby','ojaswi','deepu'],
                   'age':[21,23,22,21],
                   'subjects':['linux','html/css','node-js','php-mysql']})

# Display The Dataframe
print(df)

# Rename id column with student_id
# Rename name  column with student_name
# Rename age  column with student_age
# Rename subjects  column with Programming
df.columns=['student_id','student_name','student_age','Programming']

# Display the Dataframe
print(df)

Output:

     id    name  age   subjects
0  7058  sravan   21      linux
1  7069   bobby   23   html/css
2  7060  ojaswi   22    node-js
3  7061   deepu   21  php-mysql


   student_id student_name  student_age Programming
0        7058       sravan           21       linux
1        7069        bobby           23    html/css
2        7060       ojaswi           22     node-js
3        7061        deepu           21   php-mysql

Here we renamed,

  • id column with student_id
  • name column with student_name
  • age column with student_age
  • subjects column with Programming.

Change Column Names in Dataframe using set_axis()

This method will rename the columns of the DataFrame by using set_axis(). In this method, we pass a list containing new column names as the first parameter and as another parameter specify column axis i.e axis=1.

Syntax is as follows:

dataframe.set_axis(['new_column1',.............,'new_column n'], axis=1)

Where, dataframe is the input dataframe. Pass a list of column names as argument in set_axis() function. Also parameter axis=1 specifies the column axis.

Here we are going to rename columns using a list of column names

import pandas as pd

# Create the dataframe with four columns
df = pd.DataFrame({'id':[7058,7069,7060,7061],
                   'name':['sravan','bobby','ojaswi','deepu'],
                   'age':[21,23,22,21],
                   'subjects':['linux','html/css','node-js','php-mysql']})

# Display The Dataframe
print(df)

# Rename id column with student_id
# Rename name  column with student_name
# Rename age  column with student_age
# Rename subjects  column with Programming
df = df.set_axis([ 'student_id',
                    'student_name',
                    'student_age',
                    'Programming'],
                    axis=1)

# Display The Dataframe
print(df)

Output:

     id    name  age   subjects
0  7058  sravan   21      linux
1  7069   bobby   23   html/css
2  7060  ojaswi   22    node-js
3  7061   deepu   21  php-mysql


   student_id student_name  student_age Programming
0        7058       sravan           21       linux
1        7069        bobby           23    html/css
2        7060       ojaswi           22     node-js
3        7061        deepu           21   php-mysql

Here we renamed,

  • id column with student_id
  • name column with student_name
  • age column with student_age
  • subjects column with Programming.

Change Column names in Dataframe using str.replace()

We can str.replace() method is used to rename the old column name with the new column name. In Pandas, we use the columns attribute along with str.replace() to rename a single column at a time.

Syntax is as follows:

dataframe.columns.str.replace('old_column_name', 'new_column_name')

where,
1. dataframe is the input dataframe
2. old_column_name is the existing column and new_column_name is the replaced column

Here we are going to rename columns one by one

import pandas as pd

# Create the dataframe with four columns
df = pd.DataFrame({'id':[7058,7069,7060,7061],
                   'name':['sravan','bobby','ojaswi','deepu'],
                   'age':[21,23,22,21],
                   'subjects':['linux','html/css','node-js','php-mysql']})

# Display The Dataframe
print(df)

# Rename id column with student_id
df.columns = df.columns.str.replace('id', 'student_id')

# Rename name  column with student_name
df.columns = df.columns.str.replace('name', 'student_name')

# Rename age  column with student_age
df.columns = df.columns.str.replace('age', 'student_age')

# Rename subjects  column with Programming
df.columns = df.columns.str.replace('subjects', 'Programming')

# Display The Dataframe
print(df)

Output:

     id    name  age   subjects
0  7058  sravan   21      linux
1  7069   bobby   23   html/css
2  7060  ojaswi   22    node-js
3  7061   deepu   21  php-mysql


   student_id student_name  student_age Programming
0        7058       sravan           21       linux
1        7069        bobby           23    html/css
2        7060       ojaswi           22     node-js
3        7061        deepu           21   php-mysql

Here we renamed,

  • id column with student_id
  • name column with student_name
  • age column with student_age
  • subjects column with Programming.

Summary

In this article we discussed four methods for changing the column names in Pandas DataFrame with examples.

Related posts:

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  10. Pandas : Convert a DataFrame into a list of rows or columns in python | (list of lists)

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