How to use [] operator to add a new column In Python Pandas
We can use DataFrame indexing to create a new column in DataFrame and set it to default values.
Syntax:
df[col_name]=value
Let’s understand with an example:
Python3
# importing pandas as pd import pandas as pd # creating the dataframe df = pd.DataFrame({"Name": ['Anurag', 'Manjeet', 'Shubham', 'Saurabh', 'Ujjawal'], "Address": ['Patna', 'Delhi', 'Coimbatore', 'Greater noida', 'Patna'], "ID": [20123, 20124, 20145, 20146, 20147], "Sell": [140000, 300000, 600000, 200000, 600000]}) print("Original DataFrame :") display(df) |
Output:
Add new column in Dataframe:
Python3
df['loss'] = [40000, 20000, 30000, 60000, 200000] df |
Output:
Add a new column with default values:
Python3
df['loss'] = 'NAN'df |
Output:
Add Column to Pandas DataFrame with a Default Value
The three ways to add a column to Pandas DataFrame with Default Value.
- Using pandas.DataFrame.assign(**kwargs)
- Using [] operator
- Using pandas.DataFrame.insert()