The Python math Standard Library

While Python provides basic arithmetic operators (+, -, *, /, **), advanced scientific, engineering, and data science calculations require Python's built-in math module.

import math

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1. Rounding & Boundaries: ceil() vs. floor() vs. trunc()

import math

number = 4.28

# 1. math.ceil: Rounds UP to the next whole integer
print("Ceil:", math.ceil(number))  # Output: Ceil: 5

# 2. math.floor: Rounds DOWN to the previous whole integer
print("Floor:", math.floor(number))  # Output: Floor: 4

# 3. math.trunc: Truncates (chops off) all decimal digits
print("Truncated:", math.trunc(-4.85))  # Output: Truncated: -4

Real-World Use Case: E-Commerce Pagination

If you have 42 products and show 10 items per page:

total_products = 42
items_per_page = 10
total_pages = math.ceil(total_products / items_per_page)
print(f"Total pages needed: {total_pages}")  # Output: Total pages needed: 5

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2. Power, Roots & Logarithms

import math

# 1. Square Root
print("Square root of 64:", math.sqrt(64))  # Output: 8.0

# 2. Powers (Alternative to **)
print("2 to the power 5:", math.pow(2, 5))  # Output: 32.0

# 3. Natural Log (ln) and Base-10 Log
print("Natural log of 10:", math.log(10))     # Base e
print("Base-10 log of 1000:", math.log10(1000))  # Output: 3.0

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3. Mathematical Constants

Instead of typing hardcoded decimal approximations like 3.14159, use standard built-in constants:

import math

print("Value of Pi (π):", math.pi)  # 3.141592653589793
print("Euler's constant (e):", math.e)  # 2.718281828459045
print("Infinity:", math.inf)

Example: Area of a Circle

import math

radius = 7
area = math.pi * (radius ** 2)
print(f"Area of circle: {area:.2f} sq units")  # Output: Area of circle: 153.94 sq units

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4. Greatest Common Divisor (GCD) & Factorials

import math

# 1. Factorial of 5 (5 * 4 * 3 * 2 * 1)
print("5! =", math.factorial(5))  # Output: 120

# 2. GCD (Highest common factor of two numbers)
print("GCD of 36 and 60:", math.gcd(36, 60))  # Output: 12

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Quick Summary

• Rounding Operations: math.floor() (rounds down), math.ceil() (rounds up), and math.trunc() (chops decimals).
• Power & Roots: math.sqrt(), math.pow(), and math.isqrt() (integer square root).
• Built-in Constants: math.pi, math.e, and math.inf avoid hardcoding float precision approximations.
• Combinatorics: math.factorial(), math.gcd(), and math.comb().

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What's Next?

Now let's learn how to connect your Python applications to the live internet, call web services, and fetch real-time data with Module 21: HTTP Requests & REST APIs!

Module 21: HTTP Requests & REST APIs

Learn how REST APIs work, make GET and POST requests with the requests library, and handle status codes