Question

Calling set_fields() here doesn’t do what I’d expect. (The code’s context is a django model, but I suspect I’ve just made a python error).

class FooEdit(ModelForm):
    class Meta:
        model = Foo
        # Client should call set_fields()
        # fields = ('A', 'B')

def set_fields(self, pro):
    """Set fields correctly for status."""
    if pro:
        self.Meta.fields = ('A', 'B', 'X')
    else:
        self.Meta.fields = ('A', 'Y', 'Z', 'W')

Answer 1

You are setting class properties using an instance. For example

class A(object):
    a=0

x=A()
print x.a #prints 0
x.a=2
x.a  #prints 2
A.a  #prints 0