Python literals

Module 2 · Python literals · Lesson 3 of 6

Floats

A float — type float — is a number with a decimal point: 3.14, -0.5, 2.0. That dot is the whole difference — 2 is an integer, but 2.0 is a float, even though they're the same value.

The dot makes the difference
2int
vs
2.0float
0.1 + 0.2=0.30000000000000004

Not a bug — computers store floats in binary, so some decimals land a hair off. Every language does this.

For very large or very small numbers, you can use scientific notation with an e: 3e8 means 3 × 10⁸, or 300000000.0 — and notice the result is always a float.

One thing that catches everyone out: floats can be slightly imprecise. Run this and look closely at the third line — it's not a Python bug, it's how all computers store decimals in binary.

Run it yourselfruns in your browser · Python
main.py

For everyday work that tiny error never matters. Just know it's there, and don't be surprised when a float ends in a long tail of digits. Next: text.