[Tutor] curious struct problem

[Alan Gauld]

"Marcus Goldfish" <magoldfish at gmail.com> wrote

> I just want to troubleshoot the problem.  The error is reproduced as 
> a
> comment below the source.  As far as I know, there are no globals; I 
> am
> invoking this from a command line prompt: python demux.py foo.bin 1 
> 1

> def demux(fname, ch=1, nchan=1):
>    fmt = str(nchan) + 'h'          # nchan of short (int16)
>    blockSize = struct.calcsize(fmt)

Try a print statement here:

print fmt,' = ',blockSize

>    # file setup
>    infile  = open(fname, 'rb')
>    #outfile = open(fname + 'ch' + str(ch), 'wb')
>
>    # iterate over data
>    chunk = infile.read(blockSize)
>    while chunk:

And another print here

print chunk

Does chunk match the fmt/blockSize above?

Alan G