problem with logic in reading a binary file

[hdante]

On Mar 30, 9:23 am, "Diez B. Roggisch" <de... at nospam.web.de> wrote:
> hdante schrieb:
>
>
>
> > On Mar 30, 4:31 am, John Machin <sjmac... at lexicon.net> wrote:
> >> On Mar 30, 3:58 pm, hdante <hda... at gmail.com> wrote:
>
> >>> On Mar 29, 3:44 pm, "Bryan.Fodn... at gmail.com"
> >>> <Bryan.Fodn... at gmail.com> wrote:
> >>>> Hello,
> >>>> I am having trouble writing the code to read a binary string.  I would
> >>>> like to extract the values for use in a calculation.
> >>>> Any help would be great.
> >>>  I'm too lazy to debug your binary string, but I suggest that you
> >>> completely throw away the binary file and restart with a database or
> >>> structured text. See, for example:
> >>>  http://pyyaml.org/wiki/PyYAML
> >>>  If you have some legacy binary file that you need to process, try
> >>> creating a C program that freads the binary file and printfs a text
> >>> equivalent.
> >> ... and that couldn't be done faster and better in Python??
>
> >  No. A C struct is done faster and better than python (thus, the
> > correctness check is faster in C). Also, chances are high that there's
> > already an include file with the binary structure.
>
> That is utter nonsense. There is no "correctness check" in C. and using
> printf & thus creating strings that you then need to parse in python
> just doubles the effort needlessly.
>
> The standard-lib module "struct" is exactly what you need, nothing else.
> it sure is faster than any parsing of preprocessed data, doesn't
> introduce a language-mixture and is prototyped/tested much faster
> because of it being python - and not C-compiler and C-debugger.
>
> Alternatively, *IF* there were C-structure-declarations available for
> the binary format, the usage of ctypes would allow for roughly the same,
> even reducing the effort to create the structure definition a great deal.
>
> Diez

 Whatever you say.