How to use the update function in Python

In Python, you can use the update() method to update a dictionary or a set.

The `update()` method in dictionaries is used to add the key-value pairs from one dictionary to another. If there are the same keys, the new value will overwrite the existing value.

Here are examples of dictionaries dict1 and dict2:

dict1 = {'a': 1, 'b': 2}
dict2 = {'b': 3, 'c': 4}

dict1.update(dict2)
print(dict1)

The output is:

{'a': 1, 'b': 3, 'c': 4}

In this example, the key-value pairs of dict1 are updated by the key-value pairs of dict2, with the value of key ‘b’ being updated from 2 to 3, and the key-value pair ‘c’ being added to dict1.

The update() method in a set is used to add the elements of one set to another set. If there are duplicate elements, only one will be added.

Here are examples of sets 1 and 2 together:

set1 = {1, 2, 3}
set2 = {3, 4, 5}

set1.update(set2)
print(set1)

The output is:

{1, 2, 3, 4, 5}

In this example, the elements of set1 are updated with the elements of set2, while also adding the elements 4 and 5 from set2 that are not in set1.