[Python-ideas] SyntaxWarning for for/while/else without break or return?

[Steven D'Aprano]

On Thu, 8 Oct 2009 08:59:21 pm Stefan Rank wrote:
> In the return-but-no-break-example I had in mind::
>
>    def findit(bag):
>        for elem in bag:
>            if isgreat(elem):
>                return elem
>        else:
>            return default
>
> the use of else, though correct and arguably readable, is still
> unnecessary.

We should raise UnnecessaryNotActuallyAnError then.

There is lots of code which is correct and readable while still 
unnecessary. Should we ban these too?


mylist.extend([])

flag = True and flag

if (flag is True) is True:
    ...

while False:
    ...

if True:
    ...
elif False:
    ...

[item for item in seq if True]

alist.sort(key=lambda x: x)

and so forth. Just think, with a bit of imagination we can slow the 
compiler down by a factor of two, three or even ten, by prohibiting all 
sorts of perfectly legal code!



-- 
Steven D'Aprano