Python Operator Precedence Guide

Operator precedence determines the order in which Python performs calculations when an expression contains multiple operators. If you do not understand this order, your code will produce unexpected results.

Here is an in-depth guide to how Python prioritizes operations, ordered from Highest Priority (evaluated first) to Lowest Priority (evaluated last).

1. Parentheses ( )

Precedence: Highest

Parentheses always override standard precedence rules. Python evaluates any expression inside parentheses before moving to the outside. This is your primary tool for forcing the order of operations.

Code Example: Forcing Order

result_1 = 5 + 10 * 2
result_2 = (5 + 10) * 2

print(f"Standard: {result_1}")
print(f"Forced:   {result_2}")

Your output will appear here...

2. Exponentiation **

Precedence: Second Highest

Exponents (powers) are calculated before multiplication, division, addition, and subtraction.

Crucial Note: Exponentiation is unique because it evaluates from Right-to-Left.
2 ** 3 ** 2 is calculated as 2 ** (3 ** 2), not (2 ** 3) ** 2.

Code Example: Right-to-Left Evaluation

result = 3 * 2 ** 3
print(result)

power_chain = 2 ** 3 ** 2 
print(power_chain)

Your output will appear here...

3. Unary Operators +x, -x, ~x

Precedence: High

These operators apply to a single value immediately to their right. This includes positive signs, negative signs, and bitwise NOT.

Code Example: Unary vs Multiplication

x = 10
result = ~x * 2  
print(result)

Your output will appear here...

4. Multiplication, Division, Modulo *, /, //, %

Precedence: Medium

These four operators share the same precedence level. When they appear together, Python evaluates them from Left-to-Right.

Code Example: Left-to-Right Evaluation

result = 100 / 10 * 5  
print(result)

Your output will appear here...

5. Addition and Subtraction +, -

Precedence: Medium-Low

These happen after multiplication and division are complete. They also evaluate Left-to-Right.

Code Example: Math Order

result = 10 - 2 * 3 
print(result)

Your output will appear here...

6. Bitwise Shifts <<, >>

Precedence: Low (but higher than bitwise logic)

Bit shifts happen after arithmetic (like addition) but before bitwise AND/OR/XOR.

Code Example: Shifts vs Arithmetic

result = 8 >> 1 + 1 
print(result)

Your output will appear here...

7. Bitwise Logical Operators &, ^, |

Precedence: Lower

These operators have their own internal hierarchy:

1. Bitwise AND (&) is evaluated first.
2. Bitwise XOR (^) is evaluated second.
3. Bitwise OR (|) is evaluated last.

Code Example: Bitwise Hierarchy

result = 5 | 3 & 2
print(result)

Your output will appear here...

8. Comparison Operators ==, !=, >, <, is, in

Precedence: Very Low

All math and bitwise operations are completed before Python compares the results. All comparison operators have the same precedence level.

Code Example: Math vs Comparisons

result = 5 + 5 == 10
print(result)

Your output will appear here...

9. Boolean Logical Operators not, and, or

Precedence: Lowest

These are used to combine True/False values. They follow a specific order:

1. not (High)
2. and (Medium)
3. or (Low)

Code Example: Boolean Logic Order

result = True or False and False
print(result)

Your output will appear here...

Complete Precedence Summary Table

While memorizing this table is useful for debugging, you should not rely on it when writing code. Always use parentheses.

Writing (a + b) * c is infinitely better than writing a + b * c and hoping the next developer remembers the precedence rules. Explicit code is better than implicit code.