List Comprehension in Python

List comprehensions are elegant way to create new lists in Python. List comprehension are faster and more compact than normal functions and loops for creating list in Python.

[expression for item in list]

Suppose, we want to separate the letters of the word animal and add the letters as items of a list. The first thing that comes in mind could be using for loop.

Example 1: using for loop

letters = []

for i in 'animal':
    letters.append(i)

print(letters)

When we run the program, the output will be:

['a', 'n', 'i', 'm', 'a', 'l']

Python has an easier way to solve this issue using List Comprehension.

Example 2: using list comprehension

letters = [ letter for letter in 'animal' ]
print(letters)

In the above example, a new list is assigned to variable letters, and list contains the items of the iterable string 'animal'. We call print() function to receive the output.

List comprehension is generally more compact and faster than normal functions and loops for creating list.