Pandas DataFrame Nsmallest Method

Introduction

The Python Pandas DataFrame.nsmallest() method is used to get the first n rows of a DataFrame that are ordered by columns in ascending order. This method returns the first n rows with the smallest values in the specified columns, in ascending order. The columns that are not specified are returned as well, but not used for ordering.

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Import the Pandas library

First, we need to import the Pandas library using the import statement.

import pandas as pd

Create the DataFrame

Next, we need to create a DataFrame to work with. We can use the pd.DataFrame() function to create a DataFrame from a dictionary.

df = pd.DataFrame({'Name':['Chetan','yashas','yuvraj','Pooja','Sindu','Renuka'],'Age':  [20,25,30,18,25,20],'Height': [155,160,175,145,155,165],'Weight': [75,60,75,45,55,65]})

Use the nsmallest() method

Now, we can use the nsmallest() method on the DataFrame to retrieve the first n rows with the smallest values in the specified columns.

df.nsmallest(n, columns, keep='first')

The method takes three parameters:

• n: The number of rows to return.
• columns: The label or list of labels that specify the name of the columns to order by.
• keep: It includes ‘first’, ‘last’, ‘all’, and the default is ‘first’.
  • 'first': prioritize the first occurrence(s) in case of duplicate values.
  • 'last': prioritize the last occurrence(s) in case of duplicate values.
  • 'all': do not drop any duplicates, even if it means selecting more than n items.

Display the results

Finally, we can print the resulting DataFrame to see the first n rows with the smallest values in the specified columns.

print(df.nsmallest(n, columns, keep='first'))

Summary

The DataFrame.nsmallest() method in Python Pandas is a convenient way to retrieve the first n rows with the smallest values in specified columns of a DataFrame. By using this method, we can easily find and display the records that meet our criteria.