class PasswordPage(Page):
    ...
    def show_frame(self, page_name, arg=None):
        '''Show a frame for the given page name'''
        frame = self.frames[page_name]
        frame.tkraise()
        return frame  # return the raised frame

class ViewPasswords_InCategory(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        # home banner
        self.home_label = Label(self, text='', bg="blue", width=200, height=3, fg='white') # changed to instance variable
        self.home_label.pack(side=TOP, expand=False)

    # new function to update banner
    def set_category(self, category):
        self.home_label['text'] = category

class PasswordCategoryPage(tk.Frame):
    ...
    def showPasswordPage(self,event):
        #here need to pass the label that was clicked to the ViewPasswords_InCategory page
        self.controller.show_frame("ViewPasswords_InCategory").set_category(event.widget['text'])