Python Set difference_update() method

Python Set difference_update() method

The set.difference_update() method in Python removes the items that exist in both sets.

Syntax

set.difference_update(set1)

Parameter

set- This argument represents a set (minuend)

set1- This arguments represents a set(subtrahend)

Return

None

Example 1

# Python program explaining
# the set.difference_update() method
# initializing the first set
set1 = {"apple", "banana", "cherry"}
print("First Set:",set1)
# initializing the second set
set2 = {"google", "microsoft", "apple"}
print("Second Set:",set2)
# removes the items that are common in both sets. 
set1.difference_update(set2) 
print("After calling the difference_update() method...")
# prinitng the first set method
print("First set:",set1)
# prinitng the second set method
print("Second set:",set2)

Output

First Set: {'cherry', 'banana', 'apple'}
Second Set: {'apple', 'microsoft', 'google'}
After calling the difference_update() method...
First set: {'cherry', 'banana'} 
Second set: {'apple', 'microsoft', 'google'} 

Example 2

# Python program explaining
# the set.difference_update() method
#initializing a set with alphabets A to Z
Alphabets = {'a', 'b', 'c', 'd','e',
   'f','g','h','i',
   'j','k','l','m',
   'n','o','p','u', 
    'v','w','x','y','z'}
print("Alphabets:",Alphabets)
 # initializing set2 with vowels 
vowels = {'a', 'e', 'i','o','u'}
print("vowels: ",vowels)
# removing the common elements from the Alphabet set
# Alphabets- vowels= Consonants 
print("After subtracting the common values from Alphabets set... ")
Alphabets.difference_update(vowels)
print("Consonants: ",Alphabets) 

Output

Alphabets: {'c', 'm', 'w', 'g', 'z', 'n', 'f', 'd', 'e', 'h', 'k', 'v', 'i', 'u', 'l', 'x', 'p', 'o', 'y', 'a', 'b', 'j'}
vowels:  {'u', 'e', 'o', 'a', 'i'}
After subtracting the common values from Alphabets set...
Consonants:  {'c', 'm', 'w', 'g', 'z', 'n', 'f', 'd', 'h', 'k', 'v', 'l', 'x', 'p', 'y', 'b', 'j'} 

Example 3

# Python program explaining
# the set.difference_update() method
#initializing a set with numbers from 1 to 10
Numbers = {1,2,3,4,5,6,7,8,9,10} 
print("Numbers:",Numbers)
 # initializing set2 with even numbers
even = {2,4,6,8,10}
print("Even numbers: ",even) 
# subtracting the common even elements from Numbers
# Numbers- even=  Odd
print("After subtracting even numbers from Natural numbers... ")
Numbers.difference_update(even) 
print("Odd numbers: ",Numbers) 

Output

Numbers: {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
Even numbers:  {8, 10, 2, 4, 6}
After subtracting even numbers from Natural numbers... 
Odd numbers:  {1, 3, 5, 7, 9}