Python Operators

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In Python, operators are symbols that perform operations on variables and values.

Types

Arithmetic

• handle numeric calculations
• modulus operator % returns the reminder of the division of two numbers
• floor division operator // performs division and rounds down to the nearest whole number
  • discards the decimal to provide an integer

Operator	Name	Example	Result
+	Addition	3 + 5	8
-	Subtraction	7 - 2	5
*	Multiplication	4 * 6	24
/	Division	8 / 2	4.0
%	Modulus	10 % 3	1
//	Floor Division	15 // 4	3
**	Exponentation	2 ** 3	8

Comparison

 A comparison operator is used to compare two values.

Operator	Name	Example
==	Equal	var1 == var2
!=	Not equal	var1 != var2
>	Greater than	var1 > var2
<	Less than	var1 < var2
>=	Greater than or equal to	var1 >= var2
⇐	Less than or equal to	var1 <= var2

Logical

• perform logical operations on Boolean values
• and, or, not

Assignment

An assignment operator is used to assign a value to a variable.

Operator	Example	Equivalent
=	a = 12	a = 12
+=	a += 7	a = a + 7
-=	a -= 7	a = a - 7
*=	a *= 7	a = a * 7
/=	a /= 7	a = a / 7
%=	a %= 7	a = a % 7
//=	a //= 7	a = a // 7
**=	a **= 7	a = a ** 7
&=	a &= 7	a = a & 7
|=	a |= 7	a = a | 7
^=	a ^= 7	a = a ^ 7
>>=	a >>= 7	a = a >> 7
<<=	a << = 7	a = a << 7

Membership

Membership operators are used to test whether a value or variable is a member of a sequence or collection.

• in returns True if a value is found in the sequence
• not in returns True if a value is not found in the sequence

Identity

 Identity operators are used to compare the memory location of two objects.

• compare object identities
• Two kinds:
  • is
    • returns True if both variables point to same object
  • is not
    • Returns True if both variables do not point to the same object

Bitwise

• manipulate bits in binary representations
• & (bitwise AND)
• | (bitwise OR)
• ^ (bitwise XOR)
• ~ (bitwise NOT)
• << (left shift)
• >> (right shift)

Operate Precedence

1. Parentheses (): Highest precedence
2. Exponentiation **: Next highest
3. Multiplication, Division, Floor Division, Modulus *, /, //, %: Same precedence, evaluated left to right
4. Addition and Subtraction +, -: Same precedence, evaluated left to right
5. Bitwise Shift <<, >>: Lower than arithmetic operations
6. Bitwise AND &: Lower than shifts
7. Bitwise XOR ^: Lower than AND
8. Bitwise OR |: Lowest precedence

• if same precedence, evaluate left to right