On 5/2/2020 2:39 PM, Soni L. wrote:
On 2020-05-02 1:45 p.m., Steven D'Aprano wrote:
On Sat, May 02, 2020 at 01:20:01PM -0300, Soni L. wrote:
> > > On 2020-05-02 1:07 p.m., Steven D'Aprano wrote:
> >On Sat, May 02, 2020 at 12:50:19PM -0300, Soni L. wrote:
> >
> >> how about:
> >> > >> result = Foo.save()
> >> try:
> >> x, y = result
> >> except ValueUnpackingError:
> >> return ...
> >
> >If you do that, what benefit is ValueUnpackingError over just
> >ValueError?
> >
> >
> >
> unpacking (a generator) still doesn't wrap ValueError
Sorry, I don't understand that comment. What do you mean, "wrap"?
Unpacking a generator with too many values raises ValueError:
py> a, b = (x for x in range(3))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: too many values to unpack (expected 2)
> and ValueError is > raised a lot more than ValueUnpackingError.
Why does that matter, and how does that relate to the specific code
sample given?
Given the line of code `x, y = result`, the only possible way ValueError
could be raised is if `result` has the wrong number of items when
unpacking. So what benefit does ValueUnpackingError bring to this
example?
or if iterating result raises ValueError.
consider:
def foo():
yield from ()
raise ValueError
iterator = foo()
x, y = iterator
you get a ValueError, but not a ValueUnpackingError.
And as has been said before, what if iterating raises a ValueUnpackingError?
Rather than go over the same ground yet again, I'll stop replying to
this thread. I remain at -1 for adding this particular exception.
Eric
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