Python Set | difference_update()

The difference_update() method helps in an in-place way of differentiating the set. The previously discussed set difference() helps to find out the difference between two sets and returns a new set with the difference value, but the difference_update() updates the existing caller set.
If A and B are two sets. The set difference() method will get the (A – B) and will return a new set. The set difference_update() method modifies the existing set. If (A – B) is performed, then A gets modified into (A – B), and if (B – A) is performed, then B gets modified into (B – A).
Syntax:

A.difference_update(B) for (A - B)
B.difference_update(A) for (B - A)

The function returns None and changes the value of the existing set. 
In this example, we will get the difference between two sets and show how the difference_update works.

Python3

# Python code to get the difference between two sets
# using difference_update() between set A and set B

# Driver Code
A = {10, 20, 30, 40, 80}
B = {100, 30, 80, 40, 60}

# Modifies A and returns None
A.difference_update(B)

# Prints the modified set
print (A)

Output: 

{20, 10}