Python [méthode .pack()]

notebook = Pmw.NoteBook(self.root)
self._widgets['main_notebook'] = notebook
notebook.grid(column=0,row=0,sticky='NSWE')

## Add the "Appearance" page to the notebook ##
for name in ("Data", "Trace", "Exit") :
     page = notebook.add(name)

## Create the group menu ##
## Cell 1 - Input
group_input = Pmw.Group(notebook.page(0), tag_text='Input')
group_input.grid(column = 0, row = 1, columnspan = 2, sticky ='NSEW', padx = defaultPadding, pady = defaultPadding, ipadx = defaultPadding, ipady = defaultPadding)

## Cell 2 - Iccap Param
group_iccap = Pmw.Group(notebook.page(0), tag_text='Iccap Param')
group_iccap.grid(column = 1, row = 1, rowspan = 2, sticky ='NSEW', padx = defaultPadding, pady = defaultPadding, ipadx = defaultPadding, ipady = defaultPadding)

import Tkinter
import Pmw

class myApplication: 
    def __init__(self,root):
        self.root = root      
        self._widgets = {}
        self.initialisation()  

    def initialisation(self):     
        notebook = Pmw.NoteBook(self.root)
        self._widgets['main_notebook'] = notebook
        notebook.grid(column=0,row=0,sticky='NSWE')
        for name in ("Data", "Trace", "Exit") :
             page = notebook.add(name)
        
        group_input = Pmw.Group(notebook.page(0), tag_text='Input')
        group_input.grid(column = 0, row = 0,sticky ='NSEW')
        
        group_iccap = Pmw.Group(notebook.page(0), tag_text='Iccap Param')
        group_iccap.grid(column = 1, row = 0,sticky ='NSEW')

        Tkinter.Button(group_input.interior(),text="coucou1*************").grid(column=0,row=0)
        Tkinter.Button(group_iccap.interior(),text="coucou2**************").grid(column=0,row=0)
        
def main():
    root = Tkinter.Tk()
    root.title('My application')
    app = myApplication(root)
    root.mainloop()

if __name__ == "__main__":
    main()