Union() function in Python
Union of two given sets is the smallest set which contains all the elements of both the sets. Union of two given sets A and B is a set which consists of all the elements of A and all the elements of B such that no element is repeated.

The symbol for denoting union of sets is ‘U’
Examples:
Input:Let set A = {2, 4, 5, 6}
and set B = {4, 6, 7, 8}
Output: {2, 4, 5, 6, 7, 8}
Explanation: Taking every element of both the sets A and B,
without repeating any element, we get a
new set = {2, 4, 5, 6, 7, 8}.This new set
contains all the elements of set A and all the elements
of set B with no repetition of elements and is
named as union of set A and B.
Syntax:
set1.union(set2, set3, set4….)
In parameters, any number of sets can be given
Return value:
The union() function returns a set, which has the union of all sets(set1, set2, set3…) with set1.
It returns a copy of set1 only if no parameter is passed.
Below is the Python3 implementation of the above approach:
# Python3 program for union() function set1 = {2, 4, 5, 6} set2 = {4, 6, 7, 8} set3 = {7, 8, 9, 10} # union of two sets print("set1 U set2 : ", set1.union(set2)) # union of three sets print("set1 U set2 U set3 :", set1.union(set2, set3)) |
Output:
set1 U set2 : {2, 4, 5, 6, 7, 8}
set1 U set2 U set3 : {2, 4, 5, 6, 7, 8, 9, 10}
Practical applications:
In most of the probability problems, the concept of union of sets is needed.
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