how many bytes in an int

[Robin Becker]

Grant Edwards wrote:
> On 2004-08-09, Grant Edwards <grante at visi.com> wrote:
> 
> 
>>The struct module is the only thing I know about.  If you're
>>worried about the "C" types in the struct module changing
>>underneat you, you could do a pure Python implimentation of
>>"python-int" to/from DWORD. It's utterly trivial and shouldn't
>>take more than one or two lines of code.
> 
> 
> def toLittleEndianDWORD(i):
>     return ''.join(map(chr,[x&0xff for x in [i,i>>8,i>>16,i>>24]]))
> 
> def fromLittleEndianDWORD(s):
>     return ord(s[0]) + (ord(s[1])<<8) + (ord(s[2])<<16) + (ord(s[3])<<24)
> 

this simple code will give warnings in 2.3, I think struct is really needed.

 >>> toLittleEndianDWORD(-1)
'\xff\xff\xff\xff'
 >>> fromLittleEndianDWORD(toLittleEndianDWORD(-1))
__main__:2: FutureWarning: x<<y losing bits or changing sign will return 
a long in Python 2.4 and up
-1
 >>>
-- 
Robin Becker