How to use list comprehensions in Python?
List comprehension is a fast and easy way to create lists. The syntax is: [expression for item in iterable]
For example, we can create a list containing even numbers between 1 and 10 using a list comprehension.
even_numbers = [x for x in range(1, 11) if x % 2 == 0]
print(even_numbers)
The output result is: [2, 4, 6, 8, 10]
In addition to basic list comprehensions, we can also use nested list comprehensions to create more complex lists.
matrix = [[x*y for y in range(1, 4)] for x in range(1, 4)]
print(matrix)
The output is: [[1, 2, 3], [2, 4, 6], [3, 6, 9]]
List comprehensions can also be used in combination with conditional expressions to add conditional checks during the process of generating a list.
numbers = [x if x % 2 == 0 else x*2 for x in range(1, 11)]
print(numbers)
The output results in: [2, 2, 6, 4, 10, 6, 14, 8, 18, 10]
In conclusion, list comprehension is a powerful and versatile feature in Python that can help us quickly and succinctly create lists.