How to use apply() In Python Pandas
Since the operation we want to perform is simple we can you can directly use the apply() method without explicitly defining a function. Provide the axis argument as 1 to access the columns.
Syntax:
s.apply(func, convert_dtype=True, args=())
Parameters:
- func: .apply takes a function and applies it to all values of pandas series.
- convert_dtype: Convert dtype as per the function’s operation.
- args=(): Additional arguments to pass to function instead of series.
Return Type: Pandas Series after applied function/operation.
Example: Subtract two columns in Pandas Dataframe
Python3
import pandas as pd import numpy as np data = np.arange( 0 , 20 ).reshape( 4 , 5 ) df = pd.DataFrame(data, index = [ 'Row 1' , 'Row 2' , 'Row 3' , 'Row 4' ], columns = [ 'Column 1' , 'Column 2' , 'Column 3' , 'Column 4' , 'Column 5' ]) df[ 'diff_3_4' ] = df. apply ( lambda x: x[ 'Column 3' ] - x[ 'Column 4' ], axis = 1 ) df |
Output:
How to Subtract Two Columns in Pandas DataFrame?
In this article, we will discuss how to subtract two columns in pandas dataframe in Python.
Dataframe in use:
Contact Us