~ bit-wise unary operator

[Ladislav Andel]

Hello,
why ~ bit-wise unary operator returns -(x+1) and not bit inversion of 
the given integer?

example:
a = 7978
a = ~a
python returns -7979

but I need to get back 57557 as in C language.

which is also in binary
0001111100101010
and inverted
1110000011010101

Is here any other operator or do I have to write it on my own?

Thank you,
Lada