En Tue, 11 Dec 2007 19:28:34 -0300, eliss <[EMAIL PROTECTED]> escribi�:
> On Dec 11, 12:38 pm, Larry Bates <[EMAIL PROTECTED]> wrote: >> Diez B. Roggisch wrote: >> > Larry Bates wrote: >> >> eliss wrote: >> >>> working great so far except for one function, which returns an >> >>> unsigned int in the C version. However, in python it returns a >> signed >> >>> value to me. How can I get the unsigned value from this? I haven't >> > I'd suggest this formula: >> >> > if value < 0: >> > value = 2^32 + value + 1 > > Hi thanks for the responses but I'm afraid I don't see how either > formula works. > > Lets say I get the return value of -5, which is 1011b when it should > be 11. Then according to the formula it would be 2^4-5+1=12 > > But it should be 11... Yes, both formulae were wrong, omit the "+1" in the last one. Another way is to use a bitwise and (&) with a number whose bits are all 1's. For 4 bits (your example), you need 1111b = 0xF py> -5 & 0xF 11 For a 32bit number, you have to use x & 0xFFFFFFFF (or 0xFFFFFFFFL on older Python versions) >>> -5 & 0xffffffff 4294967291L -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
