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List Comprehension

List comprehension provides a concise way to create lists in Python. It’s a powerful tool for creating lists based on existing iterables.

Basic Syntax:

new_list = [expression for item in iterable if condition]]

• expression: What you want to do with each item.
• item: The variable representing each element in the iterable.
• iterable: The sequence (list, tuple, string, etc.) you’re working with.
• condition (optional): A filter to include only certain items.

Examples:

1. Squaring numbers:

   numbers = 1, 2, 3, 4, 5
   squares = [x**2 for x in numbers]]  # 1, 4, 9, 16, 25
   

2. Filtering even numbers:

   numbers = 1, 2, 3, 4, 5, 6
   even_numbers = [x for x in numbers if x % 2 == 0]] # 2, 4, 6
   

3. String manipulation:

   words = ["hello", "world", "python"]]
   uppercase_words = [word.upper() for word in words]] # ['HELLO', 'WORLD', 'PYTHON']]
   

4. Nested loops (equivalent to nested for loops):

   matrix = 1, 2, 3, 4
   flattened_matrix = [num for row in matrix for num in row]] # 1, 2, 3, 4
   

Nested Loops

For Loops

List comprehension offers a more readable and efficient alternative to traditional for loops when creating lists. It’s important to understand its syntax and usage to write more concise and Pythonic code.