Defining a function
We can create a function specifically for subtracting the columns, by taking column data as arguments and then using the apply method to apply it to all the data points throughout the column.
Example: Subtract two columns in Pandas dataframe
Python3
import numpy as np import pandas as pd def diff(a, b): return b - a 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['Difference_2_1'] = df.apply( lambda x: diff(x['Column 2'], x['Column 2']), axis=1) |
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: