Arithmetic Operators¶

Arithmetic operators perform mathematical operations on numeric values.

Operator Summary¶

Operator	Name	Example	Result
`+`	Addition	`3 + 2`	`5`
`-`	Subtraction	`3 - 2`	`1`
`*`	Multiplication	`3 * 2`	`6`
`/`	Division	`7 / 2`	`3.5`
`//`	Floor Division	`7 // 2`	`3`
`%`	Modulo	`7 % 2`	`1`
`**`	Exponentiation	`3 ** 2`	`9`

Basic Operations¶

a = 10
b = 3

print(a + b)   # 13 (addition)
print(a - b)   # 7  (subtraction)
print(a * b)   # 30 (multiplication)
print(a / b)   # 3.333... (true division)
print(a // b)  # 3  (floor division)
print(a % b)   # 1  (remainder)
print(a ** b)  # 1000 (10^3)

Division Types¶

True Division (`/`)¶

Always returns a float:

print(10 / 2)   # 5.0
print(7 / 2)    # 3.5
print(1 / 3)    # 0.333...

Floor Division (`//`)¶

Returns the largest integer less than or equal to the result:

print(7 // 2)    # 3
print(10 // 3)   # 3
print(-7 // 2)   # -4 (rounds toward negative infinity)

Modulo (`%`)¶

Returns the remainder after division:

print(7 % 2)     # 1
print(10 % 3)    # 1
print(15 % 5)    # 0

Unary Operators¶

x = 5
print(+x)   # 5  (unary plus)
print(-x)   # -5 (unary minus)

Exponentiation¶

print(2 ** 3)    # 8
print(2 ** 0.5)  # 1.414... (square root)
print(10 ** -2)  # 0.01

# Right-to-left associativity
print(2 ** 3 ** 2)   # 512 (2^9, not 8^2)

Assignment Operators¶

Combine assignment with arithmetic:

Operator	Example	Equivalent To
`+=`	`x += 2`	`x = x + 2`
`-=`	`x -= 2`	`x = x - 2`
`*=`	`x *= 2`	`x = x * 2`
`/=`	`x /= 2`	`x = x / 2`
`//=`	`x //= 2`	`x = x // 2`
`%=`	`x %= 2`	`x = x % 2`
`**=`	`x **= 2`	`x = x ** 2`

x = 10
x += 5   # x = 15
x *= 2   # x = 30
x //= 4  # x = 7

Type Behavior¶

Integer Operations¶

print(5 + 3)     # 8 (int)
print(5 * 3)     # 15 (int)
print(5 // 3)    # 1 (int)
print(5 / 3)     # 1.666... (float, always)

Float Operations¶

print(5.0 + 3)   # 8.0 (float)
print(5 * 3.0)   # 15.0 (float)

Complex Operations¶

print((1+2j) + (3+4j))  # (4+6j)
print((1+2j) * (3+4j))  # (-5+10j)

Common Use Cases¶

Check Even/Odd¶

if n % 2 == 0:
    print("Even")
else:
    print("Odd")

Wrap Around (Circular)¶

# Cycle through 0-9
index = (index + 1) % 10

Integer Division with Remainder¶

quotient, remainder = divmod(17, 5)
print(quotient, remainder)  # 3, 2

Summary¶

/ always returns float
// returns floor (rounds toward negative infinity)
% returns remainder
** is right-associative
Use divmod() for both quotient and remainder