Modules & Imports

A module is just a .py file. A package is a folder with an __init__.py.

Four import shapes

• import math — use as math.pi
• import math as m — alias
• from math import pi — pull a name into your namespace
• from math import pi as PI — pull and alias

Where Python looks

1. Built-ins → 2. The current file's directory → 3. Installed site-packages → 4. sys.path

Try it

1. Try from collections import defaultdict — build one.
2. Import random and generate 5 random ints between 1 and 100.