Lists & loops
Iterate, transform, and combine sequences with readable loop patterns.
How to Count, Double, and Find Max in a Python List
Three beginner-friendly Python functions that count even numbers, double each value, and find the maximum in a list using simple loops.
def count_even_numbers(numbers):
"""Return the count of even numbers in a list."""
count = 0
for num in numbers:
if num % 2 == 0:
count += 1
return count
def double_values(numbers):
"""Return a new list with each value doubled."""
doubled = []
for num in numbers:
…How to Filter Even Numbers and Square Them in Python
Create two beginner-friendly helper functions that filter even numbers and compute squares of a number list using loops, then print the results along with the sum and average.
def get_even_numbers(numbers):
evens = []
for num in numbers:
if num % 2 == 0:
evens.append(num)
return evens
def get_squares(numbers):
squares = []
for num in numbers:
squares.append(num ** 2)
return squares
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
even_numbers …Browse by section
Each section groups closely related Python snippets.
Lists & loops — Python code examples
What you will find here
This page collects lists & loops snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.
Samples vs tutorials and challenges
Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.