title: Function Variable isn't being written to by tkinter combobox
body: <p>I'm working on an application that will log events regarding a particular type of service work.</p>
  <p>The application uses a SQLite Database that I'd like to populate with 'events' in the form of Database items.</p>
  <p>My Issue is that the ComboBox's '.get()' doesn't get written to the list of data to be databased.</p>
  <p>I'm currently at PageTwo, gradually adding functionality to the pages as I go on.</p>
  <p>Please could someone show me where I've gone wrong?</p>
  <pre><code>class PageOne(tk.Frame):
      def __init__(self,parent,controller):
          tk.Frame.__init__(self,parent)
          label = ttk.Label(self,text='New Work',font=LARGE_FONT)
          label.pack(pady=10,padx=10)
  
          button3 = ttk.Button(self,text='Home',command=lambda: controller.show_frame(StartPage))
          button3.pack()
  
          sel = StringVar()
          sel2 = StringVar()
  
          l1=Label(self,text='Work Type: ')
          l1.pack()
  
          combo1 = ttk.Combobox(self, width=20,   height=40,textvariable=sel)
          combo1.pack()
          combo1['values'] = combo_values_input('Work_Dev.db','TypeData','WorkType')
  
  
          l2=Label(self,text='Customer: ')
          l2.pack()
  
          combo2 = ttk.Combobox(self, width=20,   height=40,textvariable=sel2)
          combo2.pack()
          combo2['values'] = combo_values_input('Work_Dev.db','SiteData','Site')
  
          #datalist = [str(combo1.get()),'data02',f'{date_time}','data04']
          datalist = []
  
          b1=ttk.Button(self,text=&quot;Save to DataBase&quot;,command=db_func)
          b1.pack()
  
          sel.trace('w',myupd)
          sel2.trace('w',myupd2)
  </code></pre>