jython-users

[Jython-users] problem in inner class

[Niranjan V. <nir...@ma...>]

I am defining a class within another class. The code is

 class OuterClass:

     #Inner class definition
     #
     class InnerClass:

         #inner class constructor
         #
         def __init__(self):

           #Trying to print the OuterClass 'Name' instance variable
           #But i am getting NameError
           print OuterClass.name

     #outer class constructor
     #
     def __init__(self):
         self.name="outerclass"
         self.__age=23


     def __printAge__(self,):
         print self.__age
         ic = self.InnerClass()

 if(__name__=='__main__'):
     oc = OuterClass()

 problem is i am not able to access (NameError is occuring) the Outerclass instance attributes inside the inner class constructor.

 How can i access the outerclass(both public and private) instance attributes inside inner class.

 It would be highly appreciated if anyone can give the solution for the same.


 Thanx in advance.

 Regards,
 Niranjan.V

[Jython-users] problem in inner class

[Niranjan V. <nir...@ma...>]

 I am defining a class within another class. The code is

 class OuterClass:

     #Inner class definition
     #
     class InnerClass:

         #inner class constructor
         #
         def __init__(self):

           #Trying to print the OuterClass 'Name' instance variable
          #But i am getting NameError
           print OuterClass.name

     #outer class constructor
     #
     def __init__(self):
         self.name="outerclass"
         self.__age=23


     def __printAge__(self,):
         print self.__age
         ic = self.InnerClass()

 if(__name__=='__main__'):
     oc = OuterClass()

 problem is i am not able to access (NameError is occuring) the Outerclass instance attributes inside the inner class constructor.

 How can i access the outerclass(both public and private) instance attributes inside inner class.

 It would be highly appreciated if anyone can give the solution for the same.


 Thanx in advance.

 Regards,
 Niranjan.V

Re: [Jython-users] problem in inner class

[Jan W. <j.w...@sc...>]

On Fri, Feb 01, 2002 at 11:35:23PM -0500, Niranjan V. wrote:
> I am defining a class within another class. The code is
>=20
>  class OuterClass:
>      class InnerClass:
>          def __init__(self):
>            print OuterClass.name
>      def __init__(self):
>          self.name=3D"outerclass"
>          self.__age=3D23
>      def __printAge__(self,):
>          print self.__age
>          ic =3D self.InnerClass()
>  if(__name__=3D=3D'__main__'):
>      oc =3D OuterClass()
Well, one problem I see here: Name and age are attributes of the instance=
 from
the OuterClass. In InnerClass you ask the *class* for the attribute, whil=
e only
the instance has it.
I don't think there is an easy way to get there. At first I thought neste=
d
scopes would help, but I didn't see how you get hold of the OuterClass in=
stances
attributes in the InnerClass.

Cheerio,
--=20
J.W...@sc...  -  Fon +4970719457-257 Fax-211
science+computing ag - Hagellocher Weg 71-75 - 72070 T=FCbingen
Hit any key account manager to continue.

Re: [Jython-users] problem in inner class

[Mats W. <ma...@la...>]

At 03:03 PM 2/4/2002 +0100, Jan Wender wrote:
 >On Fri, Feb 01, 2002 at 11:35:23PM -0500, Niranjan V. wrote:
 >> I am defining a class within another class. The code is
 >>
 >>  class OuterClass:
 >>      class InnerClass:
 >>          def __init__(self): >>            #Trying to print the 
OuterClass 'Name' instance variable
 >>            #But i am getting NameError
 >>            print OuterClass.name

 >Well, one problem I see here: Name and age are attributes of the instance 
from
 >the OuterClass. In InnerClass you ask the *class* for the attribute, 
while only
 >the instance has it.
 >I don't think there is an easy way to get there. At first I thought nested
 >scopes would help, but I didn't see how you get hold of the OuterClass
 >instancesattributes in the InnerClass.

Jython "inner classes" don't work the same way as in Java.
In Python, a class is a class; when you define a class
inside another class definition you've only affected the
visibility of the name bound to the class object.

If you want the InnerClass constructor to have access to
an instance of OuterClass, you have to pass it in - or
as the oft-quoted rule of Python goes: "explicit is better
than implicit".

Try this:

# Inner class definition
      class InnerClass:
          # inner class constructor
          def __init__(self, other):
            print other.name
      # outer class constructor
      def __init__(self):
          self.name="outerclass"
          self.__age=23
      def __printAge__(self):
          print self.__age
          ic = self.InnerClass(self)	# pass instance

if __name__=='__main__':
      oc = OuterClass()
      oc.__printAge__()