Python set difference_update(): Remove Matching Elements In Place

A.difference_update(*others) removes from A every element found in the other iterables and returns None. It changes the original set in place because sets are mutable.

If you need a new result while keeping A unchanged, use difference() or the - operator.

Set order: sets are unordered. Whenever an example prints a set, the displayed element order can differ between runs or Python environments.

Using difference_update() method

A={'a','b','c'}
B={'a','y','z'}
A.difference_update(B)
print(A)

Output

{'c','b'}

Using More Than Two Sets

We can use any number of sets with difference_update()

A={'a','b','c'}
B={'a','y','z'}
C={'a','c','l'}
A.difference_update(B,C)
print(A)

Output

{'b'}

difference_update() method

Using string ( iterable object ) with difference_update() method

A={'a','b','c','x','y'}
B='Alex'
A.difference_update(B)
print(A)

Output

{'c', 'y', 'a', 'b'}

Using list with difference_update() method.

A={'a','b','c'}
B=['a','x','y']
A.difference_update(B)
print(A)

Output

{'c', 'b'}

All Set Methods Updating Set Operations Questions with solutions on set
difference() union() intersection() symmetric_difference()

tuple set Dictionary Python- Tutorials

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Python set difference_update() Method

Using difference_update() method

Using More Than Two Sets

difference_update() method

Subhendu Mohapatra