Python set intersection_update() usage and example

Méthodes de集合 en Python

intersection_update() uses the intersection of the set to update the set that calls intersection_update().

The intersection of two or more sets is the set of elements common to all sets.

For more information, please visitPython set Intersection.

The syntax of junction_update() is:

A.intersection_update(*other_sets)

intersection_update() parameters

intersection_update() allows an arbitrary number of parameters (sets).

Note: *Is not part of the syntax. It is used to indicate that this method allows an arbitrary number of parameters.

Intersection_update() return value

This method returns None (meaning, no return value). It only updates the set that calls the intersection_update() method.

Assuming,

result = A.intersection_update(B, C)

When you run the code:

• result will be None

• A equals the intersection of A, B, and C

• B remains unchanged

• C remains unchanged

Example1: How to use intersection_update()?

A = {1,　2,　3,　4}
B = {2,　3,　4,　5}
result = A.intersection_update(B)
print('result =', result)
print('A =', A)
print('B =', B)

When running this program, the output is:

result = None
A = {2,　3,　4}
B = {2,　3,　4,　5,　6}

Example2: intersection_update() with two parameters

A = {1,　2,　3,　4}
B = {2,　3,　4,　5,　6}
C = {4,　5,　6,　9,　10}
result = C.intersection_update(B, A)
print('result =', result)
print('C =', C)
print('B =', B)
print('A =', A)

When running this program, the output is:

result = None
C = {4}
B = {2,　3,　4,　5,　6}
A = {1,　2,　3,　4}

Méthodes de集合 en Python