[Python-ideas] Add new `Symbol` type

[Eric V. Smith]

On 7/6/2018 11:20 AM, Flavio Curella wrote:
> I think this thread can be resolved as 'used unittest.mock.sentinel'. It 
> doesn't have 'global sentinels', but I'm not convinced they are actually 
> necessary, since `mock.sentinel` objects with the same name compare as 
> equal. Thanks to Nathaniel, I now understand that JS has global symbols 
> for historical reasons that we don't have, and I'm not convinced of 
> their usefulness.

Do all Python distributions ship with unittest.mock? I see to recall 
that Debian and/or Ubuntu strips out part of the normal distribution.

For example, dataclasses.py has a sentinel, and it includes some code to 
get a more helpful repr. It would make sense to re-use the 
unittest.mock.sentinel code, but not if that code isn't always 
guaranteed to be present.

Eric