How to add a column to a dataframe in Python

In this article, we will discuss how to add new columns to existing DataFrame in Pandas. There are multiple ways we can do this task.

Method 1: By declaring a new list as a column.

import pandas as pd 

# Define a dictionary containing Students data 
data = {'Name': ['Aby', 'Henry', 'Gowri', 'Riju'], 
		'Height': [5.1, 6.2, 5.1, 5.2], 
		'Qualification': ['Bsc', 'BA', 'Bsc', 'Bsc']} 

# dictionary into DataFrame 
df = pd.DataFrame(data) 

# Declare a list that is to be converted into a column 
address = ['New Delhi', 'Bangalore', 'Chennai', 'Patna'] 

# Using 'Address' as the column name 
df['Address'] = address 

# Observe the result 
print(df) 

Output:

    Name  Height Qualification    Address
0    Aby     5.1           Bsc  New Delhi
1  Henry     6.2            BA  Bangalore
2  Gowri     5.1           Bsc    Chennai
3   Riju     5.2           Bsc      Patna

Method 2: By using DataFrame.insert()

import pandas as pd 

# Define a dictionary containing Students data 
data = {'Name': ['Aby', 'Henry', 'Gowri', 'Riju'], 
		'Height': [5.1, 6.2, 5.1, 5.2], 
		'Qualification': ['Bsc', 'BA', 'Bsc', 'Bsc']} 

# dictionary into DataFrame 
df = pd.DataFrame(data) 

df.insert(2, "Address", ['New Delhi', 'Bangalore', 'Chennai', 'Patna'] )

print(df)

Output:

    Name  Height    Address Qualification
0    Aby     5.1  New Delhi           Bsc
1  Henry     6.2  Bangalore            BA
2  Gowri     5.1    Chennai           Bsc
3   Riju     5.2      Patna           Bsc