[Python-Dev] class name spaces inside an outer function

Greg Ewing greg.ewing at canterbury.ac.nz
Sun Apr 28 04:01:32 CEST 2013

PJ Eby wrote:
> On Sat, Apr 27, 2013 at 2:27 PM, Ethan Furman <ethan at stoneleaf.us> wrote:
>>I filed bug http://bugs.python.org/issue17853 last night.

> About the only workaround I can see is to put "Season = Season" at the
> top of a class that uses this inside a function definition,

This whole business can be avoided by doing things differently
in the first place. Instead of initialising the enum items by
calling the class, just assign a tuple of args to the name
and have the metaclass make the constructor call.

   class Planet(Enum):
     MERCURY = (3.303e+23, 2.4397e6)
     VENUS   = (4.869e+24, 6.0518e6)
     EARTH   = (5.976e+24, 6.37814e6)
     MARS    = (6.421e+23, 3.3972e6)
     JUPITER = (1.9e+27,   7.1492e7)
     SATURN  = (5.688e+26, 6.0268e7)
     URANUS  = (8.686e+25, 2.5559e7)
     NEPTUNE = (1.024e+26, 2.4746e7)

     def __init__(self, mass, radius):
       self.mass = mass
       self.radius = radius

I think that's better anyway, since it avoids aggravated
violation of DRY by repeating the class name umpteen times.


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