Op wo 1 aug. 2018 11:10 schreef Jonathan Fine <jfine2...@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/ >
_______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
