Primer

class demo(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.grid_columnconfigure(0, weight = 1)
        self.grid_rowconfigure(0, weight = 1)
        self.frame = tk.Frame(self)
        self.frame.grid_columnconfigure(0, weight = 1)
        self.frame.grid_rowconfigure(0, weight = 1)
        self.sheet = Sheet(self.frame,
                           data = [[f"Row {r}, Column {c}\nnewline1\nnewline2" for c in range(50)] for r in range(500)])
        self.sheet.enable_bindings("single_select",
                                   "drag_select",
                                   "edit_cell",
                                   "select_all",
                                   "column_select",
                                   "row_select",
                                   "column_width_resize",
                                   "double_click_column_resize",
                                   "arrowkeys",
                                   "row_height_resize",
                                   "double_click_row_resize",
                                   "right_click_popup_menu",
                                   "rc_select")
        self.sheet.extra_bindings([("begin_edit_cell", self.begin_edit_cell),
                                   ("end_edit_cell", self.end_edit_cell)])
        self.sheet.popup_menu_add_command("Say Hello", self.new_right_click_button)
        self.frame.grid(row = 0, column = 0, sticky = "nswe")
        self.sheet.grid(row = 0, column = 0, sticky = "nswe")

    def new_right_click_button(self, event = None):
        print ("Hello World!")

    def begin_edit_cell(self, event = None):
        return event.text

    def end_edit_cell(self, event = None):
        # remove spaces from user input
        if event.text is not None:
            return event.text.replace(" ", "")
        self.recalculate()


    def recalculate(self):

        pass