Lazy Looping in Practice: Building and Using Generators and Iterators

Python's for loops have one simple use: iterate over an iterable item-by-item. Everything else we think of as a looping feature (loop in reverse, loop over multiple iterables at once, or skip every other item) comes from looping helpers, which are usually implemented with generators and iterators.

In this hands‑on tutorial we'll re‑implement Python's built-in enumerate and zip functions, create our own looping helpers from scratch, and learn principles for making our looping logic more readable and more efficient.

During this tutorial, you'll learn:

• How Python's various looping helpers work under the hood
• How to create our own looping helpers
• The difference between iterables, iterators, and generators
• How Python's for loops actually work

Prerequisites:

• Comfort with Python's functions, loops, lists, and dictionaries
• Experience with comprehensions recommended but not required

This will be a very hands-on tutorial, so please bring a laptop with Python installed.

By the end of this tutorial, you'll have hands-on experience building looping helpers that make your Python code more efficient and readable, and you'll understand how Python's iteration system works under the hood.