Hi all,
I am new to Python (I just finished Guido's tutorial).
I was very surprised to learn there that the StopIteration
is used to end for loops in a standard iterator setting.
I come from C++, where the use of exceptions as control
structures is frowned upon for efficiency reasons.
What is the Python canon on this topic ? Are exceptions
considered as reasonable control structures, or is
StopIteration alone of its kind ?
Regards,
Olivier.
Jul 18 '05
10  1727 
[Peter Hansen] Exceptions are also used by some as a mechanism for
returning information from subroutines, though it's
very likely the information will still be considered
"exceptiona l" in some way (think of it as an out-of-band
mechanism for returning special info).
[Olivier Parisy] Do you have some example of this in the standard library ?
Not sure if this is what Peter had in mind, but grep for 'ValueError'.
[Peter] While some people object on stylistic grounds (or even
performance ones, in some cases) to such things, you
will likely find that exceptions are thrown around
by Python programmers more readily than you are used to.
[Olivier Parisy] That's what I wanted to know. OK.
Control-structure-y uses (esp. within a single function) are much
rarer than the ordinary use: a function signalling an exceptional
condition to its callers. This ordinary use is certainly used more
extensively in idiomatic Python code than is the case in many other
languagesa.
StopIteration is used a lot, I guess, but it's rare that you're
actually concious of that fact.
John This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics | |
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