Can't add page in a notebook

Question

I am having some trouble adding a page to a Notebook widget. The error I get is this:

AttributeError: 'function' object has no attribute 'append_page'

I assume this means the object pages in the following code has not been set to a Gtk.Notebook class.

def add_page(self, pages):
    textview = Gtk.TextView()
    textbuffer = textview.get_buffer()
    textbuffer.set_text("")
    pages.append_page(textview, Gtk.Label("New Page"))

The code that calls that is:

def on_btn_new_page_activate(self, widget):
    self.add_page(self.get_pages)

The method get_pages() is following (Probably where the problem is):

def get_pages(self):
    subjectNum = self.subjects.get_current_page()
    pages = self.subject.get_nth_page(subjectNum)
    return pages

The subjects variable is a valid Notebook fetched by the following:

self.subjects = self.builder.get_object("subjects")

Thanks.

EDIT: Now the following error occurs:

Traceback (most recent call last):
File "/home/nja/notetaker/notetaker/NotetakerWindow.py", line 100, in on_btn_new_page_activate
self.add_page(self.get_pages())
File "/home/nja/notetaker/notetaker/NotetakerWindow.py", line 73, in get_pages
pages = self.subject.get_nth_page(subjectNum)
AttributeError: 'NotetakerWindow' object has no attribute 'subject'

Answer 1

The fix is:
self.add_page(self.get_pages())

not self.add_page(self.get_pages)

the latter passes in the function self.get_pages not its return value

Edit:

from: pages = self.subject.get_nth_page(subjectNum)

to: pages = self.subjects.get_nth_page(subjectNum)

This is a simple typo we all make from time to time.