Python -v import behavior

[David]

On Wed, Apr 30, 2008 at 6:42 PM, Sean Ryan <searyan at gmail.com> wrote:
> Hi all,
> (A similar question was posted by a colleague, but did not appear to  reach
> comp.lang.python or this list).
>
> I am wondering if the -v option causes the python application to be more
> tolerant to module import warnings and / or errors.
>
> The reason is that a module is failing to import correctly (generating an
> ImportError exception).  Examining this closer we re-ran the script using
> the -v option. to find that "Unsatisfied symbol" errors we being displayed
> during import (cx_Oracle 4.3.1, python 2.5.1, HP-UX 11, oracle 9.2).
> However, the module is usable from the python prompt (when using -v)
> displayed, i.e. dir (cx_Oracle) works correctly, as does  database
> interaction.  Without the -v option the script is halted due to the
> ImportError exception.
>
> My questions are:
> 1.  Is there a way to mimic the seemingly more tolerant import behavior  of
> python -v without producing the verbose output ?
> 2.  Is the behavior described above expected and documented ?
>

If -v makes a difference, it is most likely due to timing. The output
to console slows down your app enough so that the ImportError doesn't
get raised. Try piping output to a text file. Also experiment with the
-u (unbuffered output) option.

Another possibility is that the python binary that runs (when you
launch with -v) is different to the one that the script normally runs
with (see #! line at start of script). Also try adding the -v to the
#! line instead of the command line.

Something for you to try: Making a temporary copy of the project, and
then cut out all the code except the import lines. See if that fails,
then start commenting out imports until the error goes away.

David.