Numbers 2-1 >>> 2 + 2 4 >>> 50 - 5*6 20 >>> (50 - 5*6) / 4 5.0 >>> 8 / 5 # division always returns a floating point number 1.6 2-2 >>> 17 / 3 # classic division returns a float 5.666666666666667 >>> >>> 17 // 3 # floor division discards the fractional part 5 >>> 17 % 3 # the % operator returns the remainder of the division 2 >>> 5 * 3 + 2 # result * divisor + remainder 17 2-3 >>> 5 ** 2 # 5 squared 25 >>> 2 ** 7 # 2 to the power of 7 128 3-1 In interactive mode, the last printed expression is assigned to the variable _. This means that when you are using Python as a desk calculator, it is somewhat easier to continue calculations, for example: >>> tax = 12.5 / 100 >>> price = 100.50 >>> price * tax 12.5625 >>> price + _ 113.0625 >>> round(_, 2) 113.06 This variable should be treated as read-only by the user. Don’t explicitly assign a value to it — you would create an independent local variable
with the same name masking the built-in variable with its magic behavior.