[Tutor] capturing exceptions from an exec statement

[Andreas Kostyrka]

Python 2.4.5 (#2, Mar 12 2008, 00:15:51) 
[GCC 4.2.3 (Debian 4.2.3-2)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> try:
...     exec("raise ValueError")
... except:
...     print "raised some exception"
...     import sys
...     print sys.exc_info()
... 
raised some exception
(<class exceptions.ValueError at 0xb7d83b3c>, <exceptions.ValueError instance at 0xb7d6738c>, <traceback object at 0xb7d65aa4>)
>>> 

Something like this?

Andreas

Am Dienstag, den 08.04.2008, 17:12 +1000 schrieb Garry Willgoose:
> I'm writing a (very simple) command line window for use within my  
> Tkinter GUI menu driven program (Aside: I want to provide a Matlab  
> like command line capability within an otherwise menu driven  
> program ... but where the script language is Python). The guts of  
> executing the command are (where commandtext is a text variable  
> captured from my command line window)
> 
>      try:
>        exec(commandtext)
>      except:
>        print 'failed to execute command'      # we'll do something  
> more sophisticated in due course
> 
> The question is if commandtext contains invalid python I thought exec  
> raised an exception that I could capture. I seem unable to get this  
> to throw an exception no matter what is in commandtext. I assume I'm  
> missing something simple here.
> 
> Alternatively should I open a process with popen ... I want to be  
> able to modify variables in the existing scope and the way I read  
> popen I can't do that.
> 
> 
> ====================================================================
> Prof Garry Willgoose,
> Australian Professorial Fellow in Environmental Engineering,
> Director, Centre for Climate Impact Management (C2IM),
> School of Engineering, The University of Newcastle,
> Callaghan, 2308
> Australia.
> 
> Centre webpage: www.c2im.org.au
> 
> Phone: (International) +61 2 4921 6050 (Tues-Fri AM); +61 2 6545 9574  
> (Fri PM-Mon)
> FAX: (International) +61 2 4921 6991 (Uni); +61 2 6545 9574 (personal  
> and Telluric)
> Env. Engg. Secretary: (International) +61 2 4921 6042
> 
> email:  garry.willgoose at newcastle.edu.au;  
> g.willgoose at telluricresearch.com
> email-for-life: garry.willgoose at alum.mit.edu
> personal webpage: www.telluricresearch.com/garry
> ====================================================================
> "Do not go where the path may lead, go instead where there is no path  
> and leave a trail"
>                            Ralph Waldo Emerson
> ====================================================================
> 
> 
> 
> 
> 
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