Numbers and Arithmetic Operations¶

Python supports integers, floating-point numbers, and complex numbers out of the box.

Numeric Types in Python¶

1. Integer (int): Whole numbers without decimals. Python integers have unlimited precision.
2. Floating-point (float): Numbers containing a decimal point, implemented using IEEE 754 double precision.
3. Complex (complex): Numbers written in the form $a + bj$, where $j$ is the imaginary unit.

x = 10         # int
pi = 3.14159   # float
z = 2 + 5j     # complex

print(type(x))
print(type(pi))
print(type(z))

Arithmetic Operators¶

Division: True Division vs Floor Division¶

• True division (/) always returns a floating-point number, even if the division divides evenly.
• Floor division (//) rounds down to the nearest integer.

print(8 / 4)    # Output: 2.0 (float)
print(8 // 4)   # Output: 2 (int)
print(17 // 3)  # Output: 5
print(17 % 3)   # Output: 2 (remainder)

Exponentiation and Large Numbers¶

Use ** to calculate powers:

print(2 ** 8)    # 256
print(2 ** 100)  # 1267650600228229401496703205376

In Python 3, integers automatically handle arbitrarily large numbers without buffer overflow.

Underscores in Numeric Literals¶

To improve readability of large numbers, underscores can be placed between digits:

population = 1_400_000_000
price = 10_000.50

Augmented Assignment Operators¶

Operators can be combined with = to modify a variable in-place:

count = 10
count += 5   # Equivalent to: count = count + 5 (15)
count -= 2   # Equivalent to: count = count - 2 (13)
count *= 2   # Equivalent to: count = count * 2 (26)
count /= 2   # Equivalent to: count = count / 2 (13.0)