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:

Method 1: Direct Method 

This is the __getitem__ method syntax ([]), which lets you directly access the columns of the data frame using the column name.

Example: Subtract two columns in Pandas dataframe

Output: 

Method 2: 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

Output : 

Method 3: Using apply()

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 

Output:

Method 4: Using the Assign method

assign() method assign new columns to a DataFrame, returning a new object (a copy) with the new columns added to the original ones. 

Example: Subtract two columns in Pandas dataframe

Output :