How to use the Series.transform() function in pandas

Overview

The pandas Series.transform() function applies a function on itself and produces a Series of the transformed element with the same axis shape as itself.

Syntax

Series.transform(func, axis=0)

Parameters:

  • func: This represents the function or list of functions used to transform the series elements.
  • axis: This represents the parameter needed for DataFrame compatibility. It can be 0 or index.

Code example

The following code will demonstrate how to use the Series.transform() function in pandas:

import pandas as pd
# create Series 
my_series = pd.Series([17, 10, 28, 15, 23, 7, 9, 36, 14])
 
# apply lambda function to series element
# using product()
print(my_series.transform(lambda x: x **2 - 100))
print(len(my_series))

Code explanation

In the code above:

  • Line 1: We import the pandas library.

  • Lines 4: We create Series called my_series of length 9.

  • Line 8: We pass a lambda function as an argument to the transform(), which multiplies each element in the Series by the power of 2 and subtracts 100 from each.

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