Python 3: Operators

Arithmetic Operators

Arithmetic

purpose	syntax	function
addition	a + b	add(a, b)
Subtraction	a - b	sub(a, b)
Negation	- a	neg(a)
Multiplication	a * b	mul(a, b)
Division	a / b	truediv(a, b)
Division	a // b	floordiv(a, b)
Modulo	a % b	mod(a, b)
Exponentiation	a ** b	pow(a, b)

The “function” column is the function from the “operator” module. You can use it after you import operator. example:

# -*- coding: utf-8 -*-
# Python 3

import operator

print(operator.add(3,4))  # prints 7

10.3. operator — Standard operators as functions — Python v3.3.3 documentation #mapping-operators-to-functions

Assignment Operators

# -*- coding: utf-8 -*-
# Python 3

# add and assign
c = 0
c += 1
print(c)                        # 1

# substract and assign
c = 0
c -= 2
print(c)                        # -2

# multiply and assign
c = 2
c *= 3
print(c)                        # 6

# exponent and assign
c = 3
c **= 2
print(c)                        # 9

# divide and assign
c = 7
c /= 2
print(c)                        # 3.5

# modulus (remainder) and assign
c = 13
c %= 5
print(c)                        # 3

# quotient and assign
c = 13
c //= 5
print(c)                        # 2

Note: Python doesn't support ++ or --.

Warning: ++i may not generate any error, but it doesn't do anything.

Bit Operators

Bit Operators

purpose	syntax	function
and	a & b	and_(a, b)
or	a | b	or_(a, b)
xor	a ^ b	xor(a, b)
invert	~ a	invert(a)
Right Shift	a >> b	rshift(a, b)
Left Shift	a << b	lshift(a, b)

# -*- coding: utf-8 -*-
# Python 3

# 0b101 would mean binary 101
# the "{:2b}" means print in binary, and use 2 slots.

# bitwise And
print( "{:2b}".format(0b11 & 0b10) )   # binary 10


# bitwise Or
print( "{:2b}".format(0b11 | 0b10) )   # binary 11

# xor. true if both sides differ
print( "{:2b}".format(0b00 ^ 0b10) )   # binary 10

# binary invert
print( "{:2b}".format(~ 0b1) )   # binary -10  (odd result!)

Sequence Operators

Sequence Operators

purpose	syntax	function
get item	obj[k]	getitem(obj, k)
assign item	obj[k] = v	setitem(obj, k, v)
delete item	del obj[k]	delitem(obj, k)
join	seq1 + seq2	concat(seq1, seq2)
if exist	obj in seq	contains(seq, obj)
format string	s % obj	mod(s, obj)

Boolean Operators

Boolean Operators

purpose	syntax	function
to boolean	obj	truth(obj)
not	not a	not_(a)
equal	a == b	eq(a, b)
not equal	a != b	ne(a, b)
less than	a < b	lt(a, b)
less equal	a <= b	le(a, b)
greater	a > b	gt(a, b)
greater equal	a >= b	ge(a, b)
same object	a is b	is_(a, b)
not same object	a is not b	is_not(a, b)

2. Lexical analysis — Python v3.3.3 documentation #operators