I'm having some issues with decimal.Decimal objects playing nice with custom data types. I have my own matrix and rational classes which implement __add__ and __radd__. They know what to do with Decimal objects and react appropriately.
The problem is that they only work with Decimals if the custom type is on the left (and therefore __add__ gets called), but NOT if the Decimal is on the left. The Decimal immediately throws the usual "TypeError: You can interact Decimal only with int, long or Decimal data types." without even trying my __radd__ method to see if my custom type can handle Decimals. >From the Python docs (specifically sections 3.3.7 and 3.3.8), I thought that the left object should try its own __add__, and if it doesn't know what to do, THEN try the right object's __radd__ method. I guess Decimal objects don't do this? Is there a way to change this behavior? If Decimal objects prematurely throw a TypeError before trying the __rop__, is Decimal broken, or was it designed this way? I think I'm missing something... Thanks, Blake -- http://mail.python.org/mailman/listinfo/python-list
