Operators

Introduction

Operators in Python are special symbols and keywords that allow you to perform operations on values and variables. They encompass a wide range of functionalities—from arithmetic and comparison to logical, bitwise, and assignment operations. Mastering these operators is essential for constructing expressive and efficient Python code, as they form the foundation of nearly every computation or decision-making process in your programs. Below, you’ll find concise examples for each operator to help you understand their usage and expected outcomes.

Arithmetic

Name	Symbol	Operator	Example
Addition	+	a + b	5 + 3 # 8
Division	/	a / b	10 / 4 # 2.5  (always returns a float)
Exponentiation	**	a ** b	2 ** 3 # 8
Floor Division	//	a // b	10 // 4 # 2    (always returns an integer)
Modulo	%	a % b	10 % 4 # 2
Multiplication	*	a * b	5 * 3 # 15
Negation	-	- a	- 5 # -5
Subtraction	-	a - b	10 - 3 # 7

Augmented Arithmetic

Name	Symbol	Operator	Example
Addition	+=	a += b	a = 5 b = 3 a += b # a = 8
Division	/=	a /= b	a = 10 b = 4 a /= b # a = 2.5
Exponentiation	**=	a **= b	a = 2 b = 3 a **= b # a = 8
Floor Division	//=	a //= b	a = 10 b = 4 a //= b # a = 2
Modulus	%=	a %= b	a = 10 b = 3 a %= b # a = 1
Multiplication	*=	a *= b	a = 2 b = 3 a *= b # a = 6
Subtraction	-=	a -= b	a = 10 b = 4 a -= b # a = 6

Comparison

Name	Symbol	Operator	Example
Equality	==	a == b	5 == 5 # True
Inequality	!=	a != b	5 != 10 # True
Greater Than	>	a > b	10 > 5 # True
Greater Than or Equal	>=	a >= b	10 >= 5 # True
Less Than	<	a < b	5 < 10 # True
Less Than or Equal	<=	a <= b	5 <= 5 # True
Chained Comparison	varies	a < b < c	1 < 2 < 3 # True (1 < 2) and (2 < 3)

Logical

Name	Symbol	Example
False	False	Certain values are defined to be False, including: None False Numeric zero of any type: 0, 0.0, 0j Empty sequences and collections: '' (empty string), [] (empty list), () (empty tuple), {} (empty dictionary), set(), etc.
True	True	Any object that is not explicitly False is considered True. For instance, non-empty strings, non-zero numbers, non-empty lists, and even custom objects (unless they override the truth value methods to return False) are treated as True.

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Name	Symbol	Operator	Example
Identity	is	a is b	[1] is [1] # False
Not Identity	is not	a is not b	5 is not 10 # True
Logical AND	and	a and b	True and False # False
Logical Negation	not	not a	not False # True
Logical OR	or	a or b	False or True # True
Conditional Expression	if else	x if condition else y	"Yes" if 5 > 3 else "No" # "Yes"

Sequences (Lists, Tuples, Strings)

Name	Symbol	Operator	Example
Concatenation	+	seq1 + seq2	[1, 2] + [3, 4] # [1, 2, 3, 4]
Slice Assignment		seq[i:j] = values	lst = [1, 2, 3, 4] lst[1:3] = [20, 30] # lst = [1, 20, 30, 4]
Slice Deletion		del seq[i:j]	lst = [1, 2, 3, 4] del lst[1:3] # lst = [1, 4]
Slicing		seq[i:j]	lst = [1, 2, 3, 4] lst[1:3] # [2, 3]

Dictionaries (Mappings)

Name	Symbol	Operator	Example
Indexed Assignment		obj[k] = v	d = {} d['a'] = 1 # d = {'a': 1}
Indexed Deletion		del obj[k]	d = {'a': 1} del d['a'] # d =  {}
Indexing		obj[k]	d = {'a': 1} d['a'] # 1

String Formatting

Name	Symbol	Operator	Example
String Formatting	%	s % obj	str = "Hello, %(name)s" % {"name": "Alice"}    # str = 'Hello, Alice'

Membership

Name	Symbol	Operator	Example
Containment Test	in	obj in seq	'a' in 'cat' # True
Membership Negation (Not In)	not in	a not in b	'x' not in 'hello' # True

Bitwise

Name	Symbol	Operator	Example
Bitwise And	&	a & b	6 & 3 # 2 (0b110 & 0b011 = 0b010)
Bitwise Exclusive Or (XOR)	^	a ^ b	6 ^ 3 # 5 (0b110 ^ 0b011 = 0b101)
Bitwise Inversion (NOT)	~	~ a	~5 # -6 (~0b101 yields -6 in two's complement)
Bitwise Or	|	a | b	6 | 3 # 7 (0b110 | 0b011 = 0b111)
Left Shift	<<	a << b	2 << 3 # 16 (0b10 << 3 becomes 0b10000)
Right Shift	>>	a >> b	16 >> 2 # 4 (0b10000 >> 2 becomes 0b100)

Augmented Bitwise

Name	Symbol	Operator	Example
Augmented Bitwise And	&=	a &= b	a = 6 b = 3 a &= b # a = 2 (0b110 & 0b011 = 0b010)
Augmented Bitwise Exclusive Or (XOR)	^=	a ^= b	a = 6 b = 3 a ^= b # a = 5 (0b110 ^ 0b011 = 0b101)
Augmented Bitwise Or	|=	a |= b	a = 6 b = 3 a |= b # a = 7 (0b110 | 0b011 = 0b111)
Augmented Left Shift	<<=	a <<= b	a = 5 b = 2 a <<= b # a = 20 (5 << 2 equals 5 * 2²)
Augmented Right Shift	>>=	a >>= b	a = 20 b = 2 a >>= b # a = 5 (20 >> 2 equals 20 // 2²)