hex to bin 16 bit word

[python]

Is there an other way to do this?

What to decode hex '0xC0A8' and return signed short int.
(-16216,)


Above works just wondering if there is cleaner way without writing a
function.

Bill

 

[Paul Rubin]

What to decode hex '0xC0A8' and return signed short int.

Is this right?

n = int('0xC0A8', 16)
if n >= 0xffff:
n -= 0x10000

 

[Steven D'Aprano]

Is this right?

n = int('0xC0A8', 16)
if n >= 0xffff:
n -= 0x10000

No.

.... n -= 0x10000
....49320


Should be -16216.

Personally, I don't see why the OP doesn't just use struct.unpack to
unpack a struct.

 

[Grant Edwards]

Is this right?

n = int('0xC0A8', 16)
if n >= 0xffff:
n -= 0x10000

Yes, as long as the input value doesn't exceed 0x1ffff. This is
probably better:

n = int('0xc0a8'16) & 0xffff

 

[Paul Rubin]

No.

Oops, I meant n >= 0x7fff. Checking the sign bit.

Yes, as long as the input value doesn't exceed 0x1ffff. This is
probably better:

n = int('0xc0a8'16) & 0xffff

Yeah, I was relying on the specification that the input was 16 bits.

 

[Grant Edwards]

Yes, as long as the input value doesn't exceed 0x1ffff. This is
probably better:

n = int('0xc0a8'16) & 0xffff

Oops, missed the "signed" part of the requirement.

n = int('0xc0a8',16) & 0xffff

if (n & 0x8000): n |= -1 & ~0xffff

 

[Grant Edwards]

Oops, missed the "signed" part of the requirement.

n = int('0xc0a8',16) & 0xffff

if (n & 0x8000): n |= -1 & ~0xffff

or this:

if (n & 0x8000): n = -((~n & 0x7fff) + 1)

 

[python]

snip

Thanks for all you suggestions.

This was sent via email. Original solution with struct was not
to bad but less clear that this was sent to me via email.