"Rob Williscroft" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Paul McGuire wrote in news:[EMAIL PROTECTED] in > comp.lang.python: > >> >> class Constants(object) >> pass >> >> (I guess value immutability could probably be implemented using clever >> implementations of __setattr__ and such, but is it really worth the >> bother?). >> >> Then I defined the context for my LEFT and RIGHT constants, which are >> being created to specify operator associativity, and then my constant >> fields as attributes of that object: >> >> opAssoc = Constants(object) >> opAssoc.RIGHT = 0 >> opAssoc.LEFT = 1 >> > > This is nice, but you can cut down on some of the cruft: > > class Constants( object ): > pass > > Constants.RIGHT = 0 > Constants.LEFT = 1 > > ## client code ... > print Constants.LEFT > > Rob.
One man's cruft is another man's clarity. The reason I used instances instead of just the Constants class was so that I could define a little more descriptive context for the constants, rather than simply a shortcut for importing lots and lots of constant definitions. I expect I will want to define some more constants for other parts of pyparsing, and the instance scoping helps organize them, that's all. It's really a style/taste issue at this point. What you've written will certainly work, and if Neil has many constants in his module, what you suggest would be a way to import them all at once. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
