add column to dataframe pandas with index code example

Example 1: how to add a column to a pandas df

#using the insert function:
df.insert(location, column_name, list_of_values) 
#example
df.insert(0, 'new_column', ['a','b','c'])
#explanation:
#put "new_column" as first column of the dataframe
#and puts 'a','b' and 'c' as values

#using array-like access:
df['new_column_name'] = value

#df stands for dataframe

Example 2: add an index column pandas

import numpy as np
import pandas as pd
df = pd.DataFrame({'month': [2, 5, 8, 10],
                   'year': [2017, 2019, 2018, 2019],
                   'sale': [60, 45, 90, 36]})
df.set_index('month')

Example 3: how to add new column to dataframe

# Import pandas package  
import pandas as pd 
  
# Define a dictionary containing Students data 
data = {'Name': ['Jai', 'Princi', 'Gaurav', 'Anuj'], 
        'Height': [5.1, 6.2, 5.1, 5.2], 
        'Qualification': ['Msc', 'MA', 'Msc', 'Msc']} 
  
# Convert the dictionary into DataFrame 
df = pd.DataFrame(data) 
  
# Declare a list that is to be converted into a column 
address = ['Delhi', 'Bangalore', 'Chennai', 'Patna'] 
  
# Using 'Address' as the column name 
# and equating it to the list 
df['Address'] = address 
  
# Observe the result 
df