Python collection difference() usage and example

Méthodes de collection en Python

The different() method returns the set difference of two sets.

If A and B are two sets. The set difference of A and B is a set of elements that exist only in set A and not in set B, for example:

If
A = {1,　2,　3,　4}
B = {2,　3,　9}
Then,
A　-　B = {1,　4}
B　-　A = {9}

The syntax of the difference() method in Python is:

A.difference(B)

Here, A and B are two set collections. The following syntax is equivalent to A-B.

difference() return value

The difference() method returns the difference between two sets, which is also a set. It does not modify the original set.

Example1How does the difference() function work in Python?

A = {'a', 'b', 'c', 'd'}
B = {'c', 'f', 'g'}
# Is equivalent to-B
print(A.difference(B))
# Is equivalent to-A
print(B.difference(A))

When running the program, the output is:

{'b', 'a', 'd'}
{'g', 'f'}

You can also use in Python - the operator to find the set difference.

Example2Use-The operator finds the set difference.

A = {'a', 'b', 'c', 'd'}
B = {'c', 'f', 'g'}
print(A-B)
print(B-A)

When running the program, the output is:

{'b', 'd', 'a'}
{'f', 'g'}

Méthodes de collection en Python