What is a set comprehension and dictionary comprehension?

In our earlier posts (Part 1 and Part 2) , we discussed extensively on list comprehension. In this post, I would like to conclude these ideas and see how we can extend it to other iterables in Python. A set comprehension works in a similar fashion. A set data structure in Python stores unique elements. Let's create a list of numbers

list_nos = [1,2,3,4,4,4,5,6,6,2,2,2,1,1,0]

We create a set using set comprehension as below.

set_nos = {element for element in list_nos}
print(set_nos)
---> {0, 1, 2, 3, 4, 5, 6}

Another example of a set comprehension can be seen below. Let's create a sentence or rather a string in Python.

sentence = "I am having a great day"
set_sentence = {element for element in sentence}
print(set_sentence)
---> {'t', 'e', 'h', 'I', 'm', 'v', 'y', ' ', 'n', 'g', 'a', 'd', 'i', 'r'}

List comprehension can be extended to dictionaries as well in Python. Let's create a list of strings.

list_strings = ["Hi", "Hello", "Wait", "Dry"]
dict_comprehension = {key:value for key,value in enumerate(list_strings)}
print(dict_comprehension)
---> {0: 'Hi', 1: 'Hello', 2: 'Wait', 3: 'Dry'}

In a dictionary comprehension, we enclose the expression in a "{ }" just like in a set. However, the only difference is, a dictionary has a key value pair while a set has only elements.
In general, list comprehension is widely used and is very popular. Set and dictionary comprehension are not so popular, but we must be aware of it.