Numbers & Math

Python has two everyday number types. Whole numbers are ints (5, -3), and numbers with a decimal point are floats (3.5, 0.1).

qty = 5          # int
price = 3.5      # float
total = qty * price
print(total)     # 17.5

The operators

• + add, - subtract, * multiply, / divide.
• / always gives a float: 10 / 2 is 5.0.
• // is floor division (divide and drop the remainder): 7 // 2 is 3.
• % is modulo (the remainder left over): 7 % 2 is 1.
• ** is power: 2 ** 3 is 8.

Modulo is handier than it looks. n % 2 == 0 tells you n is even, and % is how you wrap things around a clock.

print(17 // 5)   # 3
print(17 % 5)    # 2
print(3 ** 2)    # 9