[Tutor] exceptions

[dman]

On Mon, Apr 15, 2002 at 10:22:58AM +0100, alan.gauld@bt.com wrote:
| >  How do you approach error trapping and use exceptions in Python to  
| >  take care of it?  How do you for all the possible dumb user mistakes?   
|  
| My tutor contains a page on this subject, plus we just had a thread on it.
|  
| >  I mean give me the kind of thought process of how I should go about  
| >  thinking this through in planning my program. 

To echo Sean and Alan, I start out accepting only good input.  As I
see where I mess up I add rudimentary error handling and build it up
as I consider everything that can go wrong.  Often times it is just a
matter of seeing the list of exceptions a library method can raise and
doesn't necessarily require a full understanding of every possible
situation that can cause the method to fail.

| For production code I routinely put a try:/except/ 
| handler around my entire program which just says 
| "Oops something unexpected happened". But thats just 
| to shield the gentle users from unsightly stack traces. 
| I comment it out during development/testing.

I do the same thing, if the code is going to be production.  (that is,
if it will be more than a script that only I will use)  That is
especially important for a daemon that has no stdout for python to
dump a stack trace to.  Instead I must catch the exception and record
the error in the syslog so it can be tracked down later.

-D

-- 

A)bort, R)etry, D)o it right this time