What is set comprehension in Python3 and why is it so handy?
with handy code snippets too!
3 min readNov 1, 2023
What is Set Comprehension?
Set comprehension in Python is a compact way to process all or part of the elements in a collection to create a set. Similar to list comprehensions, set comprehensions allow us to transform one set or any iterable into a new set.
A set can be handy to use instead of a list because it guarantees that there are no duplicates in the set.
Syntax:
The basic syntax of a set comprehension is:
Where:
- expression is the value that will be included in the new set
- item represents each element that is drawn form the iterable
- iterable is a collection of elements that we want to iterate over (such as lists, sets, tuples, etc)
- condition is optional; it’s a filter that allows us to include only elements that meet certain criteria
Example
# using set comprehension to create a set of squares from 0 to 9
squares = {x**2 for x in range(10)}
print(squares) # Output: {0, 1, 4, 9, 16, 25, 36, 49, 64, 81}
In this example, x**2
is the expression that will be the element of the new set, x
is the item taken from the iterable range(10)
, and there's no condition, so all elements are processed.