old_contents: import tkinter as tk
  from model.Request import Request
  from webservice_caller.GoogleAPI import GoogleAPICaller
  
  class GUIApplication(tk.Frame):
      def __init__(self, master=None):
          super().__init__(master)
          self.pack()
          self.create_widgets()
  
      def create_widgets(self):
          self.departure_x = tk.Entry(self)
          self.departure_x.insert(0 ,"Depart x")
          self.departure_x.pack()
  
          self.departure_y = tk.Entry(self)
          self.departure_y.insert(0 ,"Depart y")
          self.departure_y.pack()
  
          self.destination_x = tk.Entry(self)
          self.destination_x.insert(0 ,"Arrivee x")
          self.destination_x.pack()
  
          self.destination_y = tk.Entry(self)
          self.destination_y.insert(0 ,"Arrivee y")
          self.destination_y.pack()
  
          self.request = tk.Button(self)
          self.request["text"] = "Comment y aller ?"
          self.request["command"] = self.request_itinerary
          self.request.pack(side="top")
          self.quit = tk.Button(self, text="Quitter",
                                command=self.master.destroy)
          self.quit.pack(side="bottom")
  
      def request_itinerary(self):
          request_from = [self.departure_x.get(), self.departure_y.get()]
          request_to = [self.destination_x.get(), self.destination_y.get()]
          print('Going from {} to {}'.format(request_from, request_to))
          self.request = Request(request_from,request_to)
          self.process_request()
      
      def process_request(self):
          google_api_caller = GoogleAPICaller(self.request)
          print(google_api_caller.get_possibilities())
          
  
  
new_contents: import tkinter as tk
  import tkinter.messagebox as messagebox
  from model.Request import Request
  from webservice_caller.GoogleAPI import GoogleAPICaller
  
  class GUIApplication(tk.Frame):
      def __init__(self, master=None):
          super().__init__(master)
          self.pack()
          self.fields = {'Depart x':True, 'Depart y':True, 'Arrivee x':True, 'Arrivee y':True}
          self.buttons = {'Comment y aller ?': self.request_itinerary, 'Quitter':self.master.destroy}
          self.create_widgets()
      
      def pack_fields_with_label(self):
          for title, is_mistaken in self.fields.items():
              label = tk.Label(self, text=title)
              label.pack()
              entry = tk.Entry(self)
              entry.pack()
              self.fields[title] = entry
      
      def pack_buttons(self):
          for text, command in self.buttons.items():
              button = tk.Button(self, text=text, command=command)
              button.pack()
  
      def create_widgets(self):
          self.pack_fields_with_label()
          self.pack_buttons()
  
      def request_itinerary(self):
          try:
              request_from = [self.fields['Depart x'].get(), self.fields['Depart y'].get()]
              request_to = [self.fields['Arrivee x'].get(), self.fields['Arrivee y'].get()]
              self.request = Request(request_from,request_to)
              self.process_request()
          except ValueError:
              messagebox.showinfo("Lawen", "Tu as oublie de remplir un champ")
      
      def process_request(self):
          google_api_caller = GoogleAPICaller(self.request)
          print(google_api_caller.get_possibilities())
          
  
  
subject: improve gui