Python Operators, Expressions and Operator Precedence

Python allows programmers to perform calculations, compare values, make decisions, and manipulate data using operators. When operators and operands are combined, they form an expression. Understanding operators and their precedence helps in writing correct and efficient Python programs.

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What is an Operator?

Example

```python a = 10 b = 5 c = a + b print(c) ``` Output ```text 15 ```

Here, + is an operator, while a and b are operands.

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Types of Operators in Python

Operator Type	Purpose	Examples
Arithmetic	Mathematical calculations	+, -, *, /, %, //, **
Relational (Comparison)	Compare values	==, !=, >, <, >=, <=
Logical	Combine conditions	and, or, not
Assignment	Assign values	=, +=, -=, *=
Membership	Check membership	in, not in
Identity	Compare object identity	is, is not

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Arithmetic Operators

Operator	Description	Example	Result
+	Addition	8 + 2	10
-	Subtraction	8 - 2	6
*	Multiplication	8 * 2	16
/	Division	8 / 2	4.0
//	Floor Division	9 // 2	4
%	Modulus	9 % 2	1
**	Exponentiation	2 ** 3	8

Program

```python a = 12 b = 5 print("Addition =", a + b) print("Subtraction =", a - b) print("Multiplication =", a * b) print("Division =", a / b) print("Floor Division =", a // b) print("Remainder =", a % b) print("Power =", a ** b) ```

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Relational Operators

Operator	Description
==	Equal to
!=	Not equal to
>	Greater than
<	Less than
>=	Greater than or equal to
<=	Less than or equal to

```python a = 10 b = 20 print(a < b) print(a == b) ``` Output ```text True False ```

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Logical Operators

Operator	Meaning
and	True if both conditions are True
or	True if at least one condition is True
not	Reverses the logical result

```python age = 18 print(age >= 18 and age <= 60) print(not(age > 18)) ```

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Assignment Operators

Operator	Equivalent To
=	x = 5
+=	x = x + 5
-=	x = x - 5
*=	x = x * 5
/=	x = x / 5

```python x = 10 x += 5 print(x) ```

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Membership Operators

Membership operators check whether a value exists in a sequence such as a string or list.

```python name = "Python" print("P" in name) print("Z" in name) ```

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Identity Operators

Identity operators compare whether two variables refer to the same object.

```python a = [1,2] b = a print(a is b) print(a is not b) ```

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Expressions

Examples

```python 10 + 5 a * b (x + y) / 2 ```

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Expression Evaluation

Expression evaluation is the process in which Python calculates the final value of an expression according to operator precedence and associativity.

Example

```python result = 10 + 5 * 2 print(result) ``` Output ```text 20 ```

Multiplication is performed before addition.

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Operator Precedence

Precedence (High → Low)	Operators
1	()
2	**
3	*, /, //, %
4	+, -
5	<, <=, >, >=, ==, !=
6	not
7	and
8	or

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Examples of Operator Precedence

```python print(5 + 3 * 2) print((5 + 3) * 2) print(20 / 5 + 2) print(10 > 5 and 8 < 4) ``` Output ```text 11 16 6.0 False ```

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Real-Life Examples

Situation	Operator Used
Calculate percentage	Arithmetic
Compare marks	Relational
Check age eligibility	Logical
Search an item in a list	Membership
Update account balance	Assignment

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Common Errors

Mistake	Correct Concept
Using = instead of == for comparison.	== is used to compare values.
Ignoring operator precedence.	Use parentheses when needed.
Using / expecting integer output.	/ always returns a float.
Confusing is with ==.	is checks identity, == checks value.

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Quick Revision

Concept	Remember
Operator	Performs an operation
Expression	Combination of operands and operators
Evaluation	Produces the final result
Highest Precedence	()
Arithmetic	+, -, *, /, //, %, **

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CBSE Exam Tips

• Remember the precedence order of operators.
• Practice tracing expressions step by step.
• Differentiate between = and ==.
• Know the purpose of each operator category.
• Use parentheses to improve readability.

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Summary

Operators are symbols that perform operations on data, while expressions combine operators and operands to produce results. Python supports arithmetic, relational, logical, assignment, membership, and identity operators. Understanding operator precedence and expression evaluation helps programmers write accurate, efficient, and error-free programs.