Python Math Functions: Complete Guide with the math Module

Quick answer: Learn Python's built-in math functions and the math module, including sqrt, ceil, floor, factorial, log, trigonometric functions, and constants.

Built-In Numeric Functions (No Import Needed)

print(abs(-15))       # 15
print(round(3.456, 2)) # 3.46
print(max(4, 9, 2))    # 9
print(min(4, 9, 2))    # 2
print(sum([1, 2, 3]))  # 6
print(pow(2, 5))       # 32

The math Module

For more advanced mathematical operations, Python's standard library math module needs to be imported first.

import math

Rounding functions

print(math.ceil(4.2))   # 5, rounds up
print(math.floor(4.8))  # 4, rounds down
print(math.trunc(4.8))  # 4, simply cuts off the decimal

Square root and powers

print(math.sqrt(16))     # 4.0
print(math.pow(2, 5))    # 32.0 (always returns a float, unlike the ** operator)

Factorial

print(math.factorial(5))  # 120  (5 * 4 * 3 * 2 * 1)

Logarithms

print(math.log(100, 10))  # 2.0, log base 10 of 100
print(math.log(math.e))   # 1.0, natural log
print(math.log2(8))       # 3.0, log base 2

Trigonometric functions

print(math.sin(math.pi / 2))   # 1.0
print(math.cos(0))              # 1.0
print(math.degrees(math.pi))    # 180.0
print(math.radians(180))        # 3.14159...

Useful Constants

print(math.pi)   # 3.141592653589793
print(math.e)    # 2.718281828459045
print(math.inf)  # infinity, useful as a starting value when finding a minimum

Greatest Common Divisor

print(math.gcd(12, 18))   # 6

math Module vs NumPy

The built-in math module works on single numbers. When you need the same operations applied across an entire array or column of data efficiently, NumPy's vectorised equivalents, such as numpy.sqrt() on a whole array at once, are the better choice.

Common Interview Questions

What is the difference between math.floor() and int()?

For positive numbers, they behave the same. For negative numbers, they differ: math.floor(-4.5) gives -5, while int(-4.5) gives -4, since int() truncates toward zero rather than rounding down.

Why use math.pow() instead of the ** operator?

math.pow() always returns a float, while ** returns an integer if both operands are integers, which can matter when a consistent type is needed downstream.