Why Does "~True" Result in -2 in Python?

If you try the following in your console:

~True 

you'll get "-2" 😳. Why?

Think about bool, you'll find that it is numeric in nature - It can hold two values, "True" and "False", and they are just "customized" versions of the integers 1 and 0 that only print themselves differently.

So bool is a subclass of int:

>>> type(True) <class 'bool'> >>> isinstance(True, int) True >>> True == 1 True >>> True is 1 # they're still different objects False 

Having that said, ~True evaluaes to:

~True == ~int(True) == ~1 == -2 

~ simply flips the bits. So:

1 = 00000001 ~1 = 11111110 

which is -2 in two's complement. Verifying that:

Flip all the bits, add 1 to the resulting number and interpret the result as a binary representation of the magnitude and add a negative sign (since the number begins with 1):

11111110 → 00000001 → 00000010 ↑ ↑ Flip Add 1 

Which is 2, but the sign is negative since the MSB is 1.

I hope that was clear :)