try/except in a loop

[Prasad, Ramit]

> >> 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
> 
> You left out the break in the try clause's else that I had. That break
> statement causes the for loop to exit early if there is no exception,
> and thus the for loop's else clause does not run:
> 
> >>> for obj in [ 1,2,3,4 ]:
> ...     try:
> ...             print obj
> ...     except Exception:
> ...             print 'EXCEPTION'
> ...     else:
> ...             print 'NO EXCEPTION'
> ...             break
> ... else:
> ...     print 'NO OBJECTS'
> ...
> 1
> NO EXCEPTION

Whoops, you are right. My apologies Chris!

Ramit


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

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