Add column names to dataframe in Pandas

In this tutorial, we will learn how to add column names to a dataframe in Pandas. Column names provide meaningful labels for the data, making it easier to understand and work with the dataframe.

Method 1: Using the columns attribute

One way to add column names is by directly assigning a list of names to the columns attribute of the dataframe.

Example:

    import pandas as pd

    # Create a dataframe
    df = pd.DataFrame([[1, 2], [3, 4]], columns=['A', 'B'])

    # Display the dataframe
    df.head()

Method 2: Using the rename() function

Another method is to use the rename() function to assign new column names to the dataframe. This method allows you to specify new names for specific columns or rename all columns at once.

Example:

    import pandas as pd

    # Create a dataframe
    df = pd.DataFrame([[1, 2], [3, 4]], columns=['C', 'D'])

    # Rename the columns
    df = df.rename(columns={'C': 'Column1', 'D': 'Column2'})

    # Display the dataframe
    df.head()

Method 3: Using the set_axis() function

The set_axis() function can be used to assign new column names to the dataframe. This method allows you to specify the new names as a list.

Example:

    import pandas as pd

    # Create a dataframe
    df = pd.DataFrame([[1, 2], [3, 4]])

    # Assign column names using set_axis()
    df.set_axis(['Column1', 'Column2'], axis=1, inplace=True)

    # Display the dataframe
    df.head()

Method 4: Reading from a CSV file with header

If you are reading data from a CSV file that already contains column names in the header, you can use the header parameter of the read_csv() function to automatically assign the column names.

Example:

   import pandas as pd

   # Read data from CSV file with header
   df = pd.read_csv('data.csv')
   
   # Display the dataframe
   df.head()

Method 5: Using the add_prefix() or add_suffix() functions

The add_prefix() and add_suffix() functions can be used to add a prefix or suffix to existing column names, respectively.

Example:

   import pandas as pd

   # Create a dataframe
   df = pd.DataFrame([[1, 2], [3, 4]], columns=['A', 'B'])
   
   # Add a prefix to column names
   df = df.add_prefix('Prefix_')
   
   # Add a suffix to column names
   df = df.add_suffix('_Suffix')
   
   # Display the dataframe
   df.head()

Method 6: Using the set_columns() function

The set_columns() function can be used to directly assign a list of column names to the dataframe. This method allows you to replace all existing column names with the new names.

Example:

   import pandas as pd

   # Create a dataframe
   df = pd.DataFrame([[1, 2], [3, 4]])
   
   # Assign column names using set_columns()
   df.set_columns(['Column1', 'Column2'])
   
   # Display the dataframe
   df.head()

Last Updated on May 18, 2023 by admin