[Python-Dev] PEP 435 -- Adding an Enum type to the Python standard library

[Steven D'Aprano]

On 13/04/13 10:13, Glenn Linderman wrote:

> can't define two names in the same enum to have the same value, per the PEP.


I think that's too strong a restriction. I would expect to be able to do this:

class Insect(Enum):
     wsap = 1  # Oops, needed for backward compatibility, do not remove.
     wasp = 1  # Preferred. Use this in new code.
     bee = 2
     ant = 3


Or at the very least:

class Insect(Enum):
     wasp = wsap = 1
     bee = 2
     ant = 3


I googled on "C enum" and the very first hit includes a duplicate value:

http://msdn.microsoft.com/en-AU/library/whbyts4t%28v=vs.80%29.aspx

And two examples from asm-generic/errno.h:

#define EWOULDBLOCK     EAGAIN  /* Operation would block */
#define EDEADLOCK       EDEADLK


What's the justification for this restriction? I have looked in the PEP, and didn't see one.




-- 
Steven