trying to read from dying disk

[jdh2358 at gmail.com]

I have a python file that is trying to read raw data from a raw
partition on a dying dist, eg

  f = file('/dev/sda')
  f.seek(SOMEWHERE)
  s = f.read(SOMEBYTES)

On some blocks, the read succeeds, on others it fails and an IOError is
thrown, and on others it appears to hang indefinitely and will not
respond to any attempt to kill it with 'kill -9 PID', etc.

Is there anyway to do a timeout read on this kind of file, or even to
kill the process once it hangs?

linux kernel 2.6.10
python 2.4.1

Thanks!
JDH