Using Built-in Modules (math, random, datetime)

Python comes with many useful built-in modules that you can use without installing anything.
Let’s look at three common ones: math, random, and datetime.

1. math – Advanced Math Functions

The math module gives you access to square roots, powers, constants like π, and more.

import math

print("Square root of 16 is", math.sqrt(16))
print("Pi rounded to 2 decimals:", round(math.pi, 2))

Explanation:

• math.sqrt() returns the square root.
• math.pi gives the value of π.

2. random – Generate Random Values

The random module helps with simulations, games, and randomized decisions.

import random

print("Random number from 1 to 10:", random.randint(1, 10))
print("Random choice from list:", random.choice(["apple", "banana", "cherry"]))

Explanation:

• randint(a, b) gives a random integer in the range [a, b].
• choice() selects one item randomly from a list.

3. datetime – Work with Dates and Times

The datetime module lets you manage dates, times, and durations.

import datetime

today = datetime.date.today()
print("Today's date is:", today)

now = datetime.datetime.now()
print("Current time is:", now.strftime("%H:%M"))

Explanation:

• date.today() returns today’s date.
• now.strftime() formats the current time as a string.

Summary

Module	Use Case
math	Square roots, powers, constants
random	Random numbers and choices
datetime	Dates, times, and formatting

What’s Next?

Next, you’ll learn how to import external modules that don’t come with Python by default.