Exception Handling Practices / Patterns

[frank.ruiz at gmail.com]

Appreciate the feedback. I was hoping to get as much perspective as possible. 

On Saturday, August 24, 2013 12:18:59 AM UTC-7, Dave Angel wrote:
> snarf wrote:
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> > Greetings,
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> >
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> > As I tread through my journey of OO I am trying to determine if there is a good approach for exception handling within classes.
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> >
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> > From my readings and gatherings - it seems I have found a common theme, but I am trying to solicit from the experts.
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> >
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> > Here is what I have found (I may be restating the obvious so please forgive me in advance):
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> >
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> > * Seems like exception handing within Classes is largely avoided and is typically only used when calling external libraries.
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> > * Try/Except type statements seem to be used more within modules, main functions, wrapper scripts.
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> 
> 
> Exceptions are used when useful.  I don't see any bias towards any one
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> location.
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> > * Classes should be coded in a way that exceptions 
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> 
> 
> You seem to be missing the last part of this sentence.
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> > * Better to never write your own exceptions (unless you absolutely have to).
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> 
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> If you mean to avoid writing exception classes, then I say nonsense. 
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> Just derive them from the closest meaningful exception class, so that a
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> user can combine handlers when reasonable.
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> 
> 
> > * Using Exception is typically a bad. More specific the better.
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> If you mean in an except statement, then I'd agree.
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> > * Exceptions should never fail silently. (Should exceptions always be logged?)
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> Exceptions should be caught if you can handle them, or if you need to
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> convert them to a different exception that someone further up the stack
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> can handle.  Sometimes handling means do nothing.
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> >
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> > Best site I have found for exceptions (hopefully this helps someone):
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> > * http://c2.com/cgi/wiki?ExceptionPatterns
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> 
> 
> But that's for Java.  java is not C++, and neither is it Python.  For
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> one thing, Python exception overhead is deliberately much less, and they
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> are used more freely.
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> Notice that exceptions are used to terminate for loops, and that's a
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> *normal* exit to the loop.  They also appear in other places under the
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> covers.  Don't be afraid of them.
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> 
> 
> -- 
> 
> DaveA