Python Pandas - Return a new Index with elements of index not in other and get the difference

To return a new Index with elements of index not in other and get the difference, use the index1.difference(index2) method in Pandas. This method performs a set difference operation, returning elements that exist in the first index but not in the second.

Syntax

Index.difference(other, sort=None)

Parameters

The difference() method accepts the following parameters ?

• other ? Index or array-like object to compute difference with
• sort ? Whether to sort the result (None, False, or True)

Basic Example

Let's create two Pandas indexes and find their difference ?

import pandas as pd

# Creating two Pandas indexes
index1 = pd.Index([10, 20, 30, 40, 50])
index2 = pd.Index([80, 40, 60, 20, 55])

# Display both indexes
print("Pandas Index1...")
print(index1)
print("\nPandas Index2...")
print(index2)

# Get the difference - elements in index1 but not in index2
result = index1.difference(index2)
print("\nDifference (index1 - index2)...")
print(result)

Pandas Index1...
Index([10, 20, 30, 40, 50], dtype='int64')

Pandas Index2...
Index([80, 40, 60, 20, 55], dtype='int64')

Difference (index1 - index2)...
Index([10, 30, 50], dtype='int64')

String Index Example

The difference()

import pandas as pd

# Creating string indexes
fruits1 = pd.Index(['apple', 'banana', 'orange', 'grape'])
fruits2 = pd.Index(['banana', 'mango', 'grape', 'kiwi'])

print("Fruits Index1:")
print(fruits1)
print("\nFruits Index2:")
print(fruits2)

# Find fruits in index1 but not in index2
difference = fruits1.difference(fruits2)
print("\nFruits in index1 but not in index2:")
print(difference)

Fruits Index1:
Index(['apple', 'banana', 'orange', 'grape'], dtype='object')

Fruits Index2:
Index(['banana', 'mango', 'grape', 'kiwi'], dtype='object')

Fruits in index1 but not in index2:
Index(['apple', 'orange'], dtype='object')