[Python-Dev] IO module precisions and exception hierarchy (original) (raw)

Greg Ewing greg.ewing at canterbury.ac.nz
Mon Sep 28 03:11:06 CEST 2009

Michael Foord wrote:

Some of the error messages are truly awful though as things stand, especially for someone new to Python. Try to read from a file handle opened in read mode for example: IOError: [Errno 9] Bad file descriptor

Subdividing the IOError exception won't help with that, because all you have to go on when deciding which exception to raise is the error code returned by the OS. If the same error code results from a bunch of different things, there's not much Python can do to sort them out.

The error messages produced for the various error codes could perhaps be improved, but that's an orthogonal issue.

-- Greg

More information about the Python-Dev mailing list