I think this is the kind of feature that can very easily be abused.
Whenever I want to break out of a nested loop I take this as an
opportunity to extract the loop into its own function and use the
return statement to break out of the loop. IMO this is a lot better
than having named or indexed loop control because a proper function
can later be reusable, and it lets you explain why you need to return
early in the docstring.
I agree with you that this feature can — and certainly will — be abused.
But I don't think that's relevant: when you think about it, any feature
can be abused. Example : variable are meant to allow a programmer to
keep a reference to some data, using a meaningful label. However, have
you never seen a piece of code where the variable names are so obscure
you can't easily guess what they point to ? I guess you did . But
variable aren't removed from any language for this reason !
The feature we're discussing now is, I think, a useful tool to be used
parsimoniously when the need arises, like any other.
I can see several advantages to having it in the language, as opposed to
building an ad-hoc function :
* performance : a call is not free, even less in Python
* readability : defining a function or similar moves the code
away from where it is actually needed. In the case of functions
called only once, such as these, this loss in readability can't be
balanced against the advantages of writing a function. That would be
an example a misused feature imo. I don't think big nested loops are
often reusable.
Globally, I think the indexed/labeled loops would be a useful tool in
imperative programming. Some other code styles, such as functional
programming, wouldn't need it, but isn't Python's policy to remain an
open language to allow you to code however you like it best ? Think of
other features, such as coroutines: they are a powerful tool, yet
dangerous and easily misused (I'm mostly talking about the `yield`
expression, witch can be used both to throw some output at the caller
/and/ to request input). However, coroutines /did/ make it into Python,
and I think they should remain there, because they can really be useful
and powerful if used with care ! The same reasoning applies to our case.
TL;DR : consenting adults : the blame for misusing a feature is on the
user, not on the language designer, especially when the feature is opt-in
Regards,
Alexis
_______________________________________________
Python-ideas mailing list -- python-ideas@python.org
To unsubscribe send an email to python-ideas-le...@python.org
https://mail.python.org/mailman3/lists/python-ideas.python.org/
Message archived at
https://mail.python.org/archives/list/python-ideas@python.org/message/3FZ2A5CJLDPL6L2N5TI3TD7EIKPQ24AK/
Code of Conduct: http://python.org/psf/codeofconduct/
