try/except in a loop

[Prasad, Ramit]

> > I have multiple objects, where any of them can serve my purpose..
> However
> > some objects might not have some dependencies. I can not tell before
> hand if
> > the all the dependencies exsit. What i want to is begin processing from
> the
> > 1st object, if no exception is raised, i am done.. if an exception is
> > raised, the next object is tried, etc  Something like
> >
> > objs = [... ]
> > try:
> >   obj = objs[0]
> >   obj.make()
> > except Exception, e:
> >   try:
> >       obj = objs[1]
> >       obj.make()
> >   except Exception, e:
> >      try:
> >         obj = objs[2]
> >         obj.make()
> >      except Exception, e:
> >        continue
> >
> > The problem is the length of the list of objs is variable... How can i
> do
> > this?
> 
> 
> for obj in objs:
>     try:
>         obj.make()
>     except Exception:
>         continue
>     else:
>         break
> else:
>     raise RuntimeError('No object worked')


I think you misunderstand the else clauses.

>>> for obj in [ 1,2,3,4 ]:
...     try:
...         print obj
...     except Exception:
...         print 'EXCEPTION'
...     else:
...         print 'NO EXCEPTION'
... else:
...     print 'NO OBJECTS'
...     
1
NO EXCEPTION
2
NO EXCEPTION
3
NO EXCEPTION
4
NO EXCEPTION
NO OBJECTS


Ramit


Ramit Prasad | JPMorgan Chase Investment Bank | Currencies Technology
712 Main Street | Houston, TX 77002
work phone: 713 - 216 - 5423

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