On Sun, Oct 7, 2018 at 3:45 PM Terry Reedy <tjreedy@udel.edu> wrote:
On 10/7/2018 1:34 PM, Chris Barker via Python-Dev wrote:
On Fri, Oct 5, 2018 at 3:01 PM Brett Cannon <brett@python.org <mailto:brett@python.org>> wrote:
I'm also fine with saying that keys in **kwargs that are not proper identifiers is an implementation detail.
It's not just **kwargs -- you can also use arbitrary names with setattr() / getattr() :
In [6]: setattr(foo, "4 not an identifier", "this works")
In [7]: getattr(foo, "4 not an identifier") Out[7]: 'this works'
When this behavior of set/getattr was discussed a decade or so ago, Guido said not to disable it, but I believe he said it should not be considered a language feature. There are other situations where CPython is 'looser' than the spec.
From an alternative implementation point of view, CPython's behaviour *is* the spec. Practicality beats purity and all that.
- Jeff