How can I Read/Write multiple sequential Binary/Text data files

[Christos TZOTZIOY Georgiou]

On 10 Mar 2005 09:41:05 -0800, rumours say that "Albert Tu"
<sjtu.0992 at gmail.com> might have written:

>Dear there,
>
>We have an x-ray CT system. The acquisition computer acquires x-ray
>projections and outputs multiple data files in binary format (2-byte
>unsigned integer) such as projection0.raw, projection1.raw,
>projection2.raw ... up to projection500.raw. Each file is
>2*1024*768-byte big.
>
>I would like to read those files and convert to ascii files in %5.0f/n
>format as projection0.data ... projection500.data so that our
>visualization software can undersatnd the projection images. I was
>trying to do this conversion using Python. However, I had troubles
>declaring the file names using the do-loop index. Anyone had previous
>experience?   

Regular expressions could help, but if you *know* that these are the filenames,
you can (untested code):

PREFIX= "projection"
SUFFIX_I= ".raw"
SUFFIX_O= ".data"

import glob, struct

for filename in glob.glob("%s*%s" % (PREFIX, SUFFIX_I)):
    number= filename[len(PREFIX):-len(SUFFIX_I)]
    fpi= open(filename, "rb")
    fpo= open("%s%s%s" % (PREFIX, number, SUFFIX_O), "w")
    while 1:
        datum= fpi.read(2)
        if not datum: break
        fpo.write("%5d\n" % struct.unpack("H", datum)) # check endianness!!!
    fpi.close()
    fpo.close()
-- 
TZOTZIOY, I speak England very best.
"Be strict when sending and tolerant when receiving." (from RFC1958)
I really should keep that in mind when talking with people, actually...