Greg Ewing suggested:
>> This version might be more readable:
>>
>> value = lst[2] except "No value" if IndexError
Ethan Furman asked:
> It does read nicely, and is fine for the single, non-nested, case
> (which is probably the vast majority), but how would
> it handle nested exceptions?
With parentheses.
Sometimes, the parentheses will make a complex expression ugly.
Sometimes, a complex expression should really be factored into pieces anyway.
Hopefully, these times are highly correlated.
The above syntax does lend itself somewhat naturally
to multiple *short* except clauses:
value = (lst[2]
except "No value" if IndexError
except "Bad Input" if TypeError)
and nested exception expressions are at least possible, but deservedly ugly:
value = (lvl1[name]
except (lvl2[name]
except (compute_new_answer(name)
except None if AppValueError)
if KeyError)
if KeyError)
This also makes me wonder whether the cost of a subscope
(for exception capture) could be limited to when an
exception actually occurs, and whether that might lower
the cost enough to make the it a good tradeoff.
def myfunc1(a, b, e):
assert "main scope e value" == e
e = "main scope e value"
value = (myfunc1(val1, val2, e)
except e.reason if AppError as e)
assert "main scope e value" == e
-jJ
--
If there are still threading problems with my replies, please
email me with details, so that I can try to resolve them. -jJ
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