My intent is to have a function object something like
def foo(arg1, arg2=foo.DEFAULT):
return int(do_stuff(arg1, arg2))
foo.SPECIAL = 42
foo.MONKEY = 31415
foo.DEFAULT = foo.SPECIAL
so I can call it with either
result = foo(myarg)
or
result = foo(myarg, foo.SPECIAL)
However I can't do this because foo.DEFAULT isn't defined at the
time the function is created. I'd like to avoid hard-coding
things while staying DRY, so I don't like
def foo(arg1, arg2=42)
because the default might change due to business rule changes, I
have a dangling "magic constant" and if the value of SPECIAL
changes, I have to catch that it should be changed in two places.
My current hack/abuse is to use __new__ in a class that can
contain the information:
class foo(object):
SPECIAL = 42
MONKEY = 31415
DEFAULT = SPECIAL
def __new__(cls, arg1, arg2=DEFAULT):
return int(do_stuff(arg1, arg2))
i1 = foo("spatula")
i2 = foo("tapioca", foo.MONKEY)
1) is this "icky" (a term of art ;-)
2) or is this reasonable
3) or is there a better way to do what I want?
Thanks,
-tkc
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