Python Set isdisjoint()

The isdisjoint() method returns True if two sets are disjoint sets. If not, it returns False.

Two sets are said to be disjoint sets if they have no common elements. For example:

A = {1, 5, 9, 0}
B = {2, 4, -5}

Here, sets A and B are disjoint sets.

Disjoint Sets Venn Diagram


The syntax of isdisjoint() is:

set_a.isdisjoint(set_b)

isdisjoint() Parameters

The isdisjoint() method takes a single argument (a set).

You can also pass an iterable (list, tuple, dictionary and string) to disjoint(). The isdisjoint() method will automatically convert iterables to set and checks whether the sets are disjoint or not.


Return Value from isdisjoint()

The isdisjoint() method returns

  • True if two sets are disjoint sets (if set_a and set_b are disjoint sets in above syntax)
  • False if two sets are not disjoint sets

Example 1: How isdisjoint() works?

A = {1, 2, 3, 4}
B = {5, 6, 7}
C = {4, 5, 6}

print('Are A and B disjoint?', A.isdisjoint(B))
print('Are A and C disjoint?', A.isdisjoint(C))

When you run the program, the output will be:

Are A and B disjoint? True
Are A and C disjoint? False

Example 2: isdisjoint() with Other Iterables as arguments

A = {'a', 'b', 'c', 'd'}
B = ['b', 'e', 'f']
C = '5de4'
D ={1 : 'a', 2 : 'b'}
E ={'a' : 1, 'b' : 2}

print('Are A and B disjoint?', A.isdisjoint(B))
print('Are A and C disjoint?', A.isdisjoint(C))
print('Are A and D disjoint?', A.isdisjoint(D))
print('Are A and E disjoint?', A.isdisjoint(E))

When you run the program, the output will be:

Are A and B disjoint? False
Are A and C disjoint? False
Are A and D disjoint? True
Are A and E disjoint? False