How to use the isin function on a dataframe in pandas

What is a dataframe?

Dataframe is a commonly used two-dimensional data structure. It is a table with columns and rows and is mostly used as a pandas object.

example dataframe

It requires the pandas library as shown below.

import pandas as pd

A dataframe can be formed as shown below. The following is a dataframe that contains countries that have been put in different groups and are given different a_score and b_scores. Both the scores are imaginary values for the purpose of this example.

import pandas as pd
a_score = [4, 5, 7, 8, 2, 3, 1, 6, 9, 10]
b_score = [1, 2, 3, 4, 5, 6, 7, 10, 8, 9]
country = ['Pakistan', 'USA', 'Canada', 'Brazil', 'India', 'Beligium', 'Malaysia', 'Peru', 'England', 'Scotland']
groups = ['A','A','B','A','B','B','C','A','C','C']
df = pd.DataFrame({'group':groups, 'country':country, 'a_score':a_score, 'b_score':b_score})
print(df)

isin function

The isin function is an advanced filtering method. It allows filtering of values based on another list of choices that have been selected.

Prototype

The function prototype is as follows.

selection = ['Pakistan','USA','Belgium']
df[df.country.isin(selection)]

Parameter

The selected filter is the parameter for this function.

Return value

This function returns the filtered values.

Code

import pandas as pd
a_score = [4, 5, 7, 8, 2, 3, 1, 6, 9, 10]
b_score = [1, 2, 3, 4, 5, 6, 7, 10, 8, 9]
country = ['Pakistan', 'USA', 'Canada', 'Brazil', 'India', 'Belgium', 'Malaysia', 'Peru', 'England', 'Scotland']
groups = ['A','A','B','A','B','B','C','A','C','C']
df = pd.DataFrame({'group':groups, 'country':country, 'a_score':a_score, 'b_score':b_score})
selection = ['Pakistan','USA','Belgium']
print(df[df.country.isin(selection)])

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