Python Loops: for, while, and Everything In Between
Loops are where Python programs do their real work -- processing data, transforming collections, retrying operations, and building results iteratively. Python gives you two core loop types (for and while) plus a set of control tools (break, continue, else clauses) that are more nuanced than they first appear.
This learning path starts with the basics of each loop type, moves into comparison and selection, then covers the control flow tools and common pitfalls that trip up developers at every level.
Core Loop Types
5 articlesPython for Loops
How for loops work in Python, iterating over sequences, using range(), and patterns for common tasks.
Python while Loops: Complete Guide
While loop syntax, conditions, infinite loops, sentinel values, and when while is the right choice over for.
Types of Looping in Python
Overview of every looping pattern in Python -- for, while, comprehensions, map, recursion, and when to use each.
Python for Loop vs while Loop
When to use for vs while, performance differences, readability trade-offs, and choosing the right loop for the task.
Python Looping with Indices
Using enumerate, range with len, and zip to access both elements and indices without C-style counter patterns.
Loop Control and Flow
7 articlesPython break and continue
How break and continue alter loop flow, with clear examples showing when each improves readability vs. harms it.
Python pass vs continue vs break
Side-by-side comparison of the three loop control statements, with flowcharts and use cases for each.
How to Break Out of Nested Loops in Python
Strategies for exiting nested loops: flags, functions, exceptions, and itertools patterns.
else Clauses on Loops
Python's unique for/else and while/else syntax -- what it means, when it runs, and practical use cases.
Why Is My Loop Infinite?
Common causes of infinite loops, how to diagnose them, and defensive patterns to prevent runaway iteration.
Python range() Function
How range works, memory efficiency, start/stop/step parameters, and common patterns with range in loops.
xrange in Python: Complete Guide
The history of xrange vs range across Python 2 and 3, and what happened during the transition.