Eli Bendersky wrote:
For instance, it is sometime non-trivial to know which exceptions some
function may throw. When you write a try...raise statement, you think
hard about covering all the bases. In an expression you're unlikely to,
Speak for yourself. I don't think I would put any less
thought into which exception I caught with an except
expression as I would for an except statement.
In fact, an except expression may even make it easier
to catch exceptions in an appropriately targeted way.
For example, a pattern frequently encountered is:
result = computation(int(arg))
and you want to guard against arg not being a
well-formed int. It's tempting to do this:
try:
result = computation(int(arg))
except ValueError:
abort("Invalid int")
But that's bad, because the try clause encompasses
too much. Doing it properly requires splitting up the
expression:
try:
i = int(arg)
except:
abort("Invalid int")
else:
result = computation(i)
With an except expression, it could be written:
result = computation(int(arg)
except ValueError: abort("Invalid int"))
--
Greg
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