Sets and Unions in Python

The Set is an unordered collection of items. Every element is unique (no duplicates) and must be immutable. However, the set itself is mutable (we can add or remove items). The union operation is also a method of set, set.union().

The SETS module provides classes for constructing and manipulating unordered collections of unique elements. Common uses include membership testing, removing duplicates from a sequence, and computing standard math operations on sets such as intersection, union, difference, and symmetric difference. To understand how it works, try the following code:

The result is a set of unique words in the sentence.

Like sets in mathematics, sets helps in carrying out functions as an intersection and difference which can be of great use.

Symmetric_difference provides those elements that are present in either one of the sets so, set1.symmetric_difference(set2) is same as set2.symmetric_difference(set1)

Now let’s have a look at the result of set1.union(set2)

More elements can be added to a set as follows:

But a set cannot have duplicate entries so you cannot add the same number again and again.

While “add function” allows you to add only one element at a time, you can add more than one element with the help of update function.

Let’s now see the magic of copy() function

https://docs.python.org/2/library/sets.html