Expression can be simplified on list

[Ned Batchelder]

On Wednesday, September 14, 2016 at 5:00:02 PM UTC-4, Lawrence D’Oliveiro wrote:
> On Thursday, September 15, 2016 at 8:13:05 AM UTC+12, Terry Reedy wrote:
> > Because True is the default, object need not and at least in CPython 
> > does not have a __bool__ (or __len__) method.
> 
> If they had to (in the absence of which a bool() cast would not work), then that would help prevent problems like the one I previously linked to, don’t you think?

Requiring an explicit conversion method wouldn't help the "midnight is False"
problem: it was *caused* by an explicit conversion method.  From the article:

> A Python bug was opened in 2012 about midnight as False, but it was closed
> soon thereafter as "invalid". The time class was documented to work that way
> and someone had created a __nonzero__() (now __bool__()) method for time to
> implement that behavior.

--Ned.