# What is the use of the "union" function in Python?

In Python, the **union()** function is used to perform the union operation on sets. The union of two or more sets is a new set that contains all the unique elements from the participating sets. The **union()** function can take one or more sets as arguments and returns a new set that is the union of all the sets. Here's an example:

```
set1 = {1, 2, 3}
set2 = {3, 4, 5}
set3 = {5, 6, 7}
union_set = set1.union(set2, set3)
print(union_set) # Output: {1, 2, 3, 4, 5, 6, 7}
```

In this example, the **union()** function is used to compute the union of **set1**, **set2**, and **set3**. The resulting set **union_set** contains all the unique elements from these sets.

The **union()** function can also be invoked using the pipe operator (**|**) as a shorthand notation:

```
set1 = {1, 2, 3}
set2 = {3, 4, 5}
set3 = {5, 6, 7}
union_set = set1 | set2 | set3
print(union_set) # Output: {1, 2, 3, 4, 5, 6, 7}
```

Both approaches produce the same result: a new set that contains all the elements from the participating sets, with duplicates removed.

The **union()** function is useful when you need to combine multiple sets and obtain a single set containing all the unique elements. It can be particularly handy for set operations such as merging data, finding the combined set of values, or performing set comparisons.