Variable not recognized in the listener - Jython Swing

I'm developing a simple window that performs some operations at closure. This is my code extract:

from javax.swing import *
from java.awt import *
from java.awt.event import *
from java.io import *
import javax.swing.table.DefaultTableModel as DefaultTableModel

class registro(JFrame):
   def __init__(self):
      super(registro, self).__init__()
      self.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)
      self.setExtendedState(JFrame.MAXIMIZED_BOTH)

      #[...]

      headers = ('Data e orario', 
                 'Personale UO Q&A', 
                 'Tipologia di attività'.decode('utf-8'),
                 'Personale incontrato con strutture di appartenenza',
                 'Note')
      self.model = DefaultTableModel([["","","","",""]], headers)
      self.table = JTable(self.model)

      #[...]

      self.addWindowListener(self.onClose())

      #[...]

   def onClose(self):
      class saver(WindowAdapter):
         tableModel = self.model
         def windowClosing(self, event):
            print tableModel #HERE IS THE ERROR!!!!!!!!!
      return saver()

The error reported on the highlighted line is the following:

NameError: global name 'tableModel' is not defined

Although I have declared the variable inside the listener (to avoid misunderstanding between the two self), I don't understand why it has never been recognized. I'm almost a novice with object-oriented programming and Swing windows on Jython, and I hope this is not my (very) serious shortcoming!

Many thanks in advance.

There's a fairly subtle scope issue here, which is mostly about Python syntax, but also about what code you want to have access to the tableModel. The tableModel variable is not visible by default because you are inside the onClose() function. A defensive solution to this is to explicitly pass the needed variable into the new saver object. I personally prefer this as it more explicitly declares the inputs for saver objects.

class WindowAdapter:
    None

class App:
    def __init__(self):
        self.model = 'DUMMYMODEL'

    def onClose(self):
        class Saver(WindowAdapter):
            def __init__(self,tableModel):
                WindowAdapter.__init__(self)
                self.tableModel = tableModel

            def windowClosing(self,event):
                print (self.tableModel)
        return Saver(self.model)


if __name__ == '__main__':
    app = App()
    sv = app.onClose()
    sv.windowClosing(event=None)

(This code is cut down and in pure Python to show it is largely scoping related.)

An alternative would be using the Python global keyword to expose the tableModel variable to all lower scopes.

class WindowAdapter:
    None

class App:
    def __init__(self):
        self.model = 'DUMMYMODEL'

    def onClose(self):
        global tableModel
        tableModel = self.model

        class Saver(WindowAdapter):
            def windowClosing(self,event):
                print (tableModel)
        return Saver()


if __name__ == '__main__':
    app = App()
    sv = app.onClose()
    sv.windowClosing(event=None)