Python · Chapter 24 of 45

Python Modules

A module is any Python file (`.py`) that can be imported. Use `import module` or `from module import name` to reuse code.

Python ships with a huge STANDARD LIBRARY: `math`, `random`, `os`, `sys`, `datetime`, `json`, `re` and many more.

Import styles

`import math` — use as `math.sqrt(9)`. `from math import sqrt` — use as `sqrt(9)`. `import math as m` — alias.

Create `helpers.py` in the same folder and `import helpers` to use its functions.

Example 1 (python)

import math
print(math.sqrt(16))
print(math.pi)

Output

4.0
3.141592653589793

Use math module for advanced numeric functions.

Example 2 (python)

from random import choice
print(choice(["red", "green", "blue"]))

Output

green

Import a single function directly.

💡 Note: Circular imports (A imports B imports A) are a common bug. Restructure your modules to break the cycle.