Op wo 1 aug. 2018 11:10 schreef Jonathan Fine <jfine2358@gmail.com>:
You're right to be cautious. My understanding of PEP 505 is that #13. a ?. b ?. __str__ #14. (a ?. b) ?. __str__ are not equivalent. The first is None, and the other is None.__str__. That looks like a gotcha.
No. None.?__str__ produces None, even though None has a __str__ attribute. I am pretty sure a?.b?.c == (a?.b)?.c and more generically chain_A ?. chain_B == (chain_A) ?. chain_B Stephan
(By the way, it was not my intention to catch you out. I'm simply looking for clarity. I wasn't aware of the gotcha until I started answering myself the question I had asked you.)
However, the None object is somewhat special, in that all it's methods and double-under (dunder) methods. And one of them is __bool__. And we can't add or change the attributes of None.
Chris, you don't have to reply to this. But I would be pleased if an expert could either tell me that my neck is safe, or produce a value of 'a' that cuts it off (so to speak).
-- Jonathan _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/