[Tutor] how to see a number as two bytes

[Luke Paireepinart]

Nice mention of the struct module, Alan.  I had forgotten about it and
I just finished an app that really could've been simplified by it.  I
might retool it to use struct when I have to revisit it for the next
part of my class assignment.

On Tue, Oct 21, 2008 at 3:34 PM, shawn bright <nephish at gmail.com> wrote:
> Thanks for all your help on this, gents.
> found what works.
> shawn
>
> On Mon, Oct 20, 2008 at 6:06 PM, Alan Gauld <alan.gauld at btinternet.com>
> wrote:
>>
>> "shawn bright" <nephish at gmail.com> wrote
>>
>>> i have a script that needs to send a number as two bytes.
>>> how would i be able to see a number expressed as a hi byte and a lo byte?
>>
>> One way is to use the struct module.
>> It has the advantage of allowing selection of big endian(>) or little
>> endian(<) representation etc. The H symbol can be used for a short
>> integer - ie 2 bytes...
>>
>> eg
>>
>>>>> import struct
>>>>> b = struct.pack(">H", 279)
>>>>> b
>>
>> '\x01\x17'
>>>>>
>>>>> b = struct.pack("<H", 279)
>>>>> b
>>
>> '\x17\x01'
>>>>>
>>
>> Note that Python will print bytes with printable representations as
>> the character form but the data is still two bytes.
>>
>> eg
>>>>>
>>>>> struct.pack("H", 33)
>>
>> '!\x00'
>>>>>
>>>>> chr(33)
>>
>> '!'
>>
>>
>> HTH,
>>
>> --
>> Alan Gauld
>> Author of the Learn to Program web site
>> http://www.freenetpages.co.uk/hp/alan.gauld
>>
>>
>>
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