On Sun, Jan 7, 2018 at 9:09 AM, Eric V. Smith <e...@trueblade.com> wrote:
> On 1/3/2018 1:17 PM, Eric V. Smith wrote: > >> I’ll open an issue after I have time to read this thread and comment on >> it. >> > > https://bugs.python.org/issue32513 > I need to think though how __eq__ and __ne__ work, as well as the ordering > operators. > > My specific concern with __ne__ is that there's one flag to control their > generation, but python will use "not __eq__" if you don't provide __ne__. I > need to think through what happens if the user only provides __eq__: does > dataclasses do nothing, does it add __ne__, and how does this interact with > a base class that does provide __ne__. Maybe dataclasses should only ever provide __eq__ and always assume Python's default for __ne__ kicks in? If that's not acceptable (maybe there are cases where a user did write an explicit __ne__ that needs to be overridden) I would recommend the following rule: - If there's an __eq__, don't do anything (regardless of whether there's an __ne__) - If there no __eq__ but there is an __ne__, generate __eq__ but don't generate __ne__ - If neither exists, generate both -- --Guido van Rossum (python.org/~guido)
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