python - tkinter GUI doesn't appear? -

small problem here, code seem clean tkinter gui doesn't appear ? can seem figure out. gui / code report form type.

thanks in advance

from tkinter import *  class fichedesignalement(frame):     def __init__(self):         frame.__init__(self)          programme = frame()         programme.pack(side="top", fill="both", expand=true)         programme.grid_rowconfigure(0, weight=5)         programme.grid_columnconfigure(0, weight=5)          self.pages = {}         onepage in (startprogram, informationspage):             start_page = onepage(programme, self)             self.pages[onepage] = start_page             start_page.grid(row=0, column=0, sticky="nsew")         self.show_pages(startprogram)      def show_pages(self, cont):         see_start_page = self.pages[cont]         see_start_page.tkraise()   class startprogram(frame):     def __init__(self, parent, controller):         frame.__init__(self, parent, controller)         label = label(self, text="fiche de signalement", font=large_font)         label.pack(padx=10, pady=10)          start_button = button(self, text="commencer", command=lambda: controller.see_page(informationspage))         start_button.pack()   class informationspage(frame):     def __init__(self, parent, controller):         frame.__init__(self, parent, controller)          label = label(self, text="informations sur le suspect", font=large_font)         label.pack(side="top", fill="both", expand=true, padx=10, pady=10)          person_suspected = label(self, text="prenom")         person_suspected.grid(row=0, column=0, padx=10, pady=10)         first_name = entry(self)         first_name.grid(row=0, column=1, padx=10, pady=10)          person_suspected_2 = label(self, text="nom")         person_suspected_2.grid(row=0, column=2, padx=10, pady=10)         last_name = entry(self)         last_name.grid(row=0, column=3, padx=10, pady=10)          person_height = label(self, text="grandeur")         person_height.grid(row=1, column=0, padx=10, pady=10)         size_height = entry(self)         size_height.grid(row=1, column=1, padx=10, pady=10)          person_weight = label(self, text="poids")         person_weight.grid(row=1, column=2, padx=10, pady=10)         size_weight = entry(self)         size_weight.grid(row=1, column=3, padx=10, pady=10)  app = fichedesignalement() app.mainloop() 

in addition indentation errors , missing import statements , missing definition of large_font, have problem:

label = label(self, text="informations sur le suspect") label.pack(side="top", fill="both", expand=true, padx=10, pady=10)  person_suspected = label(self, text="prenom") person_suspected.grid(row=0, column=0, padx=10, pady=10) 

both label , person_suspected share same parent (self), 1 uses pack , 1 uses grid. can't use both of them widgets share common parent. must use grid or pack.