[issue9401] automatically try forward operations when reverse operations are NotImplemented

[Georg Brandl]

Georg Brandl <georg at python.org> added the comment:

This might work for (normally) commutative operations like multiplication and addition, but what about those like subtraction?  If the interpreter uses the non-reversed method automatically, it has to apply semantics, but the semantics depend on the type and cannot be guessed by the interpreter.  Also, even for normally commutative operations some type may want to behave non-commutative.  With this in mind, this cannot be implemented without major headaches both for the implementation and backwards compatibility.

----------
nosy: +georg.brandl
resolution:  -> rejected
status: open -> closed

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue9401>
_______________________________________