On Sat, Apr 23, 2022 at 10:18:05PM +0900, Stephen J. Turnbull wrote:
malmiteria writes:
If O1 and O2 are refactored into N1(GP) and N2(GP) the MRO as it was before refactoring was essentially N1, GP, N2, GP, as what was O1 before refactoring is equivalent to N1, GP after refactoring. After refactoring, the MRO is now N1, N2, GP. Which do behave differently, in general.
Nobody denies that.
I denied the first part, and still do. There is no possible valid MRO that goes [N1, GP, N2, GP] because that lists the same class twice. Such a thing was possible in Python 1.x and 2.x "old-style" (classic) classes, it was a bug in the way classic classes generated the MRO, and it caused bugs in code that hit those cases. (Fortunately those cases were rare, so most people didn't notice.) -- Steve