String to Hex

[Michael Foord]

How do you safely turn an arbitrarily long signed hex string into a
long integer ?
e.g. -0x55aff8080000

When treating them as hex literals I'm getting future warnings that
from 2.4 hex values greater than sys.maxint will always return
positive values. I've had to treat them as strings and write a
function to turn them into longs a character at a time ! I couldn't
find a built in function that would do this for me.

Regards,

Fuzzy

http://www.voidspace.org.uk/atlantibots/pythonutils.html