Brtdku

i'm using kivy for building an app screen with 3 screens.
my main screen ( class Base) is showing data from a SQL request.
i would like the user to be able to update these data using a button.
first this class Base is called in the screen manager which is itself called in my root class.
So my question is , how do i clear the data in my class Base and update it with the new data?

i tried to clear the data in my class screen manager.
the refresh function is called from the root class.
i have the below error:
'ScreenManager uses remove_widget only for removing Screens'

from kivy.app import App

from kivy.uix.screenmanager import ScreenManager, Screen

from kivy.uix.boxlayout import BoxLayout

from kivy.uix.gridlayout import GridLayout

from kivy.uix.button import Button

from kivy.uix.label import Label

from sql import runsql2

from kivy.core.window import Window



    class Manager(ScreenManager):

        def __init__(self):

            super(Manager, self).__init__()



            for i in range(2):

                txt = 'Screen {}'.format(i)

                lbl = Label(text=txt)

                screen = Screen(name=txt)

                screen.add_widget(lbl)

                self.add_widget(screen)



            base=Base('main')

            self.add_widget(base)



        def refresh(self):

            self.clear_widgets(screens='main')

            base=Base('main')

            self.add_widget(base)





    class Nav(GridLayout):



        def __init__(self,sm=None):

            super(Nav, self).__init__()



            self.sm = sm

            self.cols =3

            self.size_hint = (1,0.1)

            self.add_widget(Button(text="Clearing Screen", on_release=self.change))

            self.add_widget(Button(text="Go screen 2", on_release=self.goscreen))

            self.add_widget(Button(text="Quit", on_release=self.quit))



        def change(self, btn):

            #self.sm.current = btn.text

            self.sm.current='main'



        def quit(self,ins):

            exit()



        def goscreen(self,ins):

            self.sm.current='Screen 1'



    class Base(Screen):

        def __init__(self,name):

            super(Base, self).__init__()

            self.lay=GridLayout()

            self.name=name

            self.bout=['[color=33ff99]Refresh[/color]','',"","","","","","","","",""]

            self.data=runsql2()

            self.lay.cols = 11

            self.titre=['[color=ff9900]Market[/color]', '[color=ff9900]B/S[/color]', '[color=ff9900]Volume[/color]', '[color=ff9900]Contract[/color]',

                        '[color=ff9900]C/P[/color]', '[color=ff9900]Expiry[/color]', '[color=ff9900]Strike[/color]', '[color=ff9900]Price[/color]',

                        '[color=ff9900]Account[/color]', '[color=ff9900]Give up Member[/color]', '[color=ff9900]Allocation Account[/color]']



            #self.lay.add_widget(Button(text='[color=33ff99]Refresh[/color]', size_hint=(1, 0.15), markup=True,on_release=self.do))

            for i in range(11):

                self.lay.add_widget(Label(text='', size_hint=(1, 0.15)))

            for j in range(11):

                self.lay.add_widget(Label(text=str(self.titre[j]),size_hint=(0.2,0.2),markup=True))

            long = len(self.data)

            for i in range(long):

                for j in range(11):

                    self.lay.add_widget(Label(text=str(self.data[i][j])))

            self.add_widget(self.lay)



    class Root(BoxLayout):



        def __init__(self):

            super(Root, self).__init__()

            self.orientation = "vertical"

            #Window.clearcolor = (0.6, 0.6, 0.6,1)

            sm = Manager()



            self.add_widget(Nav(sm=sm))

            self.add_widget(sm)

            self.add_widget(Button(text='refresh',size_hint=(0.2,0.2),on_release=self.refresh))

            Window.size = (1500, 900)



        def refresh(self,ins):

            sm=Manager()

            sm.refresh()



    class TestApp(App):

        def build(App):

            return Root()



    if __name__ == '__main__':

        TestApp().run()