Whether you’re just starting with Python or looking to optimize your code, mastering loops in Python is important. In this article we’ll explore everything from looping through a list to nested loops, parallel loops, infinite loops, and even one-line for loops. Let’s dive in!
What is a Loop in Python?
A loop in Python is a programming structure that allows you to repeat a block of code multiple times. Rather than writing the same code over and over again, you can use a loop to run it automatically as many times as needed.
Example:
This will print “Hello!” five times — without having to write print("Hello!") five times!
Why Use Loops in Python?
Loops are incredibly useful because they:
🔁 Reduce code repetition
🚀 Automate repetitive tasks
📊 Process items in a list, tuple, dictionary, or array
⏳ Run code until a condition is met (or not met)
📁 Loop through files in directories
🎯 Make your code efficient, scalable, and clean
Types of Loops in Python
Python mainly provides three types of loops:
1. For Loop
2. While Loop
3. Nested Loops
For Loop
Used when you want to iterate over a sequence (like a list, tuple, string, or range):
While Loop
Used when you want to repeat code while a condition is true:
Nested Loops
Loops inside loops. Common in pattern printing, matrices, and combinations:
Looping Through Arrays, Sets, and Dictionaries in Python
Loop Through Array Python
Loop Through Set Python
Loop Over Dict Python
Python Add Time Delay in For Loop
Add delay using time.sleep():
Looping Tricks & Tips
Loop with counter Python:
Loop in reverse Python:
Loop through files in directory Python:
Other Loop Features in Python
Loop Control Statements:
break – exits the loop prematurely
continue – skips to the next iteration
pass – does nothing (used as a placeholder)
When to Use Which Loop?
| Task | Best Loop Type |
|---|---|
| Iterating over list, tuple, string | for loop |
| Repeating task until condition | while loop |
| Creating patterns or grid logic | nested loops |
| Continuous monitoring or polling | infinite while loop |
Conclusion
Whether you’re looping through arrays, using nested loops, parallelizing loops, or writing elegant one-liners, Python makes it easy. Understanding how to use for and while loops in Python, and when to apply each, is key to writing efficient code.