[New-bugs-announce] [issue9401] automatically try forward operations when reverse operations are NotImplemented

[Michael Gilbert]

New submission from Michael Gilbert <michael.s.gilbert at gmail.com>:

in order to make overrides simpler, and more obvious to average developers, it would be very useful to automatically call the forward operations (e.g. __mul__) when the reverse operations (e.g. __rmul__) are NotImplemented.  

i spent quite a bit of time trying to discover why x*3 worked (where x is a class that i created with a __mul__ method); whereas 3*x wouldn't. this feature would really help since in most applications the same behavior is expected from forward and reverse operations.

for now, i am content with doing this manually, but it would be nice if it were automated.  all of my reverse operations just do:

    def __rmul__( self , other ):
        return self.__mul__( other )

where i manually check the type of other in the forward operation, and then handle it appropriately.

thanks for considering this.

best wishes,
mike

----------
components: Interpreter Core
messages: 111833
nosy: Michael.Gilbert
priority: normal
severity: normal
status: open
title: automatically try forward operations when reverse operations are NotImplemented
type: feature request
versions: Python 2.5, Python 2.6, Python 2.7, Python 3.1

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