The One-Liner Trick Every Python Coder Should Know

Boost your Python skills with this powerful one-liner trick! Learn how to write cleaner, faster, and more efficient code using list comprehensions.

Image Generated Using Leonardo AI

You ever look at someone’s Python code and think, How did they write that in one line? Meanwhile, you’ve got a full-blown five-line loop doing the same thing.

Yeah, I’ve been there too.

Python is all about writing clean, readable code, but sometimes, we overthink things. There’s a trick that makes you look like a Python pro instantly: list comprehensions.

The Old Way vs. The Pythonic Way

Let’s start simple. You’ve got a list of numbers, and you want to square each one. Here’s how most beginners (and even some experienced coders) would do it:

numbers = [1, 2, 3, 4, 5]
squared = []
for num in numbers:
    squared.append(num ** 2)
print(squared)

It works. But it’s also longer than it needs to be.

Now, let’s rewrite that in true Python style:

squared = [num ** 2 for num in numbers]
print(squared)

That’s it. One line. Same result.

This isn’t just a cool party trick — it’s a feature built into Python to make your code more readable and efficient.