Méthode d'utilisation et exemple de l'intersection() de la collection Python

Méthodes de collections en Python

The intersection() method will return a new set containing all elements common to all sets.

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

A = {1,　2,　3,　4}
B = {2,　3,　4,　　9}
C = {2,　4,　9　10}
Then,
A∩B = B∩A = {2,　3,　4}
A∩C = C∩A = {2,　4}
B∩C = C∩B = {2,　4,　9}
A∩B∩C = {2,　4}

The syntax of intersection() in Python is:

A.intersection(*other_sets)

intersection() parameters

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

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

Intersection() return value

The intersection() method returns the intersection of set A with all sets passed as parameters.

If no parameters are passed to intersection(), it will return a shallow copy of the set (A).

Example1: How does intersection() work?

A = {2,　3,　5,　4}
B = {2,　5,　100}
C = {2,　3,　8,　9,　10}
print(B.intersection(A))
print(B.intersection(C))
print(A.intersection(C))
print(C.intersection(A, B))

When running this program, the output is:

{2,　5}
{2}
{2,　3}
{2}

More examples

A = {100,　7,　8}
B = {200,　4,　5}
C = {300,　2,　3}
D = {100,　200,　300}
print(A.intersection(D))
print(B.intersection(D))
print(C.intersection(D))
print(A.intersection(B, C, D))

When running this program, the output is:

{100}
{200}
{300}
set()

You can also use the & operator to find the intersection of sets

Example3: Use the & operator to set the intersection

A = {100,　7,　8}
B = {200,　4,　5}
C = {300,　2,　3,　7}
D = {100,　200,　300}
print(A & C)
print(A & D)
print(A & C & D)
print(A & B & C & D)

When running this program, the output is:

{7}
{100}
set()
set()

Méthodes de collections en Python