On 16 November 2016 at 17:50, Ryan Gonzalez <rym...@gmail.com> wrote: > If someone decided to be weird and have __add__ and __iadd__ do two > different things, this would completely break that. Granted, that's a stupid > idea to begin with, but it's still poor justification for the code breakage.
If you think of a = a + 1 as "assigning the value of the expression a + 1 to a" and a += 1 as "incrementing a by 1" it's neither weird nor stupid. There are some well-known invariants (for example, that the value of a after the operation should be one more than the value before) that would be confusing to violate, but there are plenty of other aspects of the behaviour that are not so fundamental, and which can safely and sensibly differ between the two operations. Paul PS Note for anyone who wants to take this off on a wild tangent - my above comment is *in the context of Python as it has been defined for 20+ years*. If you want to write a new language, you can make your own judgement about any or all of this, and the success of your language will be the measure of how reasonable your ideas are... _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
