add column to empty df pandas 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 empty column to dataframe pandas

>>> import numpy as np
>>> import pandas as pd
>>> df = pd.DataFrame({"A": [1,2,3], "B": [2,3,4]})
>>> df
   A  B
0  1  2
1  2  3
2  3  4
>>> df["C"] = ""
>>> df["D"] = np.nan
>>> df
   A  B C   D
0  1  2   NaN
1  2  3   NaN
2  3  4   NaN

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