Operator precedence and evaluation order in Python

Introduction

Operator precedence tells us which math or logic operation happens first in a calculation. Evaluation order is the sequence in which parts of the expression are solved.

When you write math expressions with multiple operations like +, -, *, /

When you combine logical conditions using and, or, not

When you want to understand why a complex expression gives a certain result

When debugging code that uses many operators together

When you want to write clear code without extra parentheses

Syntax

Python

result = expression_with_operators

Operators like *, / have higher precedence than +, - so they run first.

Use parentheses () to change the order and make your code clearer.

Examples

Multiplication (*) happens before addition (+), so 3*4=12, then 2+12=14.

Python

result = 2 + 3 * 4

Parentheses force addition first: 2+3=5, then 5*4=20.

Python

result = (2 + 3) * 4

Division and multiplication have the same precedence, so evaluation goes left to right: 10/2=5.0, then 5.0*3=15.0.

Python

result = 10 / 2 * 3

and has higher precedence than or, so False and False is False, then True or False is True.

Python

result = True or False and False

Sample Program

This program shows how operator precedence and evaluation order affect the results of expressions.

Python

a = 5 + 2 * 3
b = (5 + 2) * 3
c = 10 / 2 * 4
d = True or False and False
print(f"a = {a}")
print(f"b = {b}")
print(f"c = {c}")
print(f"d = {d}")

Important Notes

Remember that multiplication and division happen before addition and subtraction.

When operators have the same precedence, Python evaluates them from left to right.

Use parentheses to make your code easier to read and avoid mistakes.

Summary

Operator precedence decides which operations run first.

Evaluation order is left to right for operators with the same precedence.

Parentheses can change the order and improve clarity.