Precedence and Associativity of Operators in Python

1. What is Operator Precedence

Operator precedence determines the order in which operators are evaluated in an expression.

result = 10 + 5 * 2
print(result)  # 20, not 30

Multiplication (*) has higher precedence than addition (+).

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2. What is Operator Associativity

Associativity determines the direction of evaluation when operators have the same precedence.

result = 100 / 10 / 2
print(result)  # 5.0

Division is left-to-right associative: (100 / 10) / 2

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3. Using Parentheses to Override Precedence

result = (10 + 5) * 2
print(result)  # 30

Parentheses explicitly control evaluation order.

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4. Arithmetic Operator Precedence

result = 2 + 3 * 4 - 5
print(result)  # 9

Evaluation order:

1. *

2. +

3. -

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5. Comparison and Logical Precedence

result = 10 > 5 and 5 > 2
print(result)  # True

Order:

1. Comparison (>)

2. Logical AND (and)

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6. Logical Operator Hierarchy

result = True or False and False
print(result)  # True

Order:

1. not

2. and

3. or

So this becomes: True or (False and False)

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7. Assignment Precedence

x = y = 10 + 5
print(x, y)  # 15 15

Assignment (=) has lower precedence than arithmetic operators.

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8. Exponentiation Associativity (Right to Left)

result = 2 ** 3 ** 2
print(result)  # 512

Evaluated as: 2 ** (3 ** 2) = 2 ** 9

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9. Bitwise Operator Precedence

result = 5 & 3 | 2
print(result)

Order:

1. &

2. |

Bitwise operations follow strict precedence for predictable results.

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10. Complex Expression Evaluation Example

result = 5 + 2 ** 3 * 4 > 20 and not False
print(result)  # True

Step-by-step:

1. Exponentiation → 2 ** 3 = 8

2. Multiplication → 8 * 4 = 32

3. Addition → 5 + 32 = 37

4. Comparison → 37 > 20 → True

5. Logical NOT → not False → True

6. AND → True and True → True

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Operator Precedence Table (High → Low)

Precedence	Operator
Highest	()
	**
	+x, -x, ~x
	*, /, //, %
	+, -
	<<, >>
	&
	^
	`
	Comparisons (==, !=, >, <, >=, <=)
	not
	and
Lowest	or

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Associativity Summary

Operator Type	Associativity
Most operators	Left → Right
Exponentiation (**)	Right → Left
Assignment (=)	Right → Left

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Best Practices

• Use parentheses for readability and predictability

• Avoid overly complex expressions

• Break expressions into multiple lines if logic becomes unclear

• Never rely on memory for precedence in critical logic

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Enterprise Relevance

Understanding precedence ensures:

• Accurate business rule logic

• Correct financial calculations

• Reliable conditional flows

• Bug-free algorithm design

This is critical in:

• Quant systems

• Validation engines

• Rule-based AI logic

• Workflow automations

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