how to do reading of binary files?

Grant Edwards grante at visi.com
Fri Jun 8 16:32:55 CEST 2007


On 2007-06-08, jvdb <streamservenl at gmail.com> wrote:

> I have a binary (pcl) file.
> In this file i want to search for specific codes (like <0C>). I have
> tried to solve it by reading the file character by character, but this
> is very slow. Especially when it comes to files which are large
> (>10MB) this is consuming quite some time.
> Does anyone has a hint/clue/solution on this?

I'd memmap the file.

http://docs.python.org/lib/module-mmap.html

If you prefer it to appear as an array of bytes instead of a
string, the various numeric/array packags can do that.

Numarray:  http://stsdas.stsci.edu/numarray/numarray-1.5.html/module-numarray.memmap.html
Vmaps:     http://snafu.freedom.org/Vmaps/Vmaps.html
Numpy:     <documentation is not free>

Since I can't point you to Numpy docs, here's a link to a
newsgroup thread with an example for numpy:

http://groups.google.com/group/comp.lang.python/browse_frm/thread/c63c3e281df99897/2336baa98386d5e7

-- 
Grant Edwards                   grante             Yow! I like your SNOOPY
                                  at               POSTER!!
                               visi.com            



More information about the Python-list mailing list