mso...@linuxmail.org wrote:
> Hello,
>
> I want to make a certain subset of public attributes available through
> an interface.
>
> The client should not need to know the names of the attributes.
>
> Here is some code with the important parts missing. Anyone care to
> fill in the missing parts?
>
>
> class C:
> def __init__(self):
> self.a = 4
> self.b = 6
> self.c = 8
> self._set_vars([self.a, self.b]) # This call might need to be
> done differently
>
> def get_vars(self):
> # add code here...
>
> def _set_vars(self, vars):
> # add code here...
>
>
> c = C()
> print c.get_vars()
> c.a = 9
> print c.get_vars()
>
>
> This is the desired output
> [4, 6] # Values of c.a and c.b
> [9, 6] # Values of c.a and c.b
>
> The important part is that the change to c.a is reflected in the call
> to get_vars(). get_vars() and _set_vars() might be moved to a base
> class,
> and therefore should not have attribute names hard coded in them.
>
> I don't have a specific problem that I'm trying to solve. I would
> just like
> to know how this sort of thing could be done.
I'd do it roughly like this:
class Base(object):
EXPORTED_VARIABLES = []
def get_vars(self):
all_variables = set(sum((getattr(cls, "EXPORTED_VARIABLES", []) for
cls in self.__class__.mro()), []))
for varname in all_variables:
yield getattr(self, varname)
class A(Base):
EXPORTED_VARIABLES = ["a"]
a = "A!"
class B(Base):
EXPORTED_VARIABLES = ["b"]
b = "B!"
class C(A,B):
pass
a = A()
b = B()
c = C()
print list(a.get_vars())
print list(b.get_vars())
print list(c.get_vars())
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