Kivy Count the No. of ToggleButtons that are ON on pressing a "Counter" Button

Question

In this code, I have a bunch of seats (ToggleButtons) and I want to count the no. of togglebuttons that are selected or switched ON when pressing the Button "Counter". I'm not sure if, for getting the result, I must individually Call a function from all the ToggleButtons (seats) or Call a single function in the main button "Counter". Also if possible, I need their Ids printed too.

Main Code:

from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.lang import Builder
from kivy.uix.widget import Widget
from kivy.uix.screenmanager import Screen,ScreenManager


class Main(Screen):
    def counter(self,widget):
        pass # what to put here? or do u have any other method
class Manager(ScreenManager):
    pass
kv=Builder.load_file("test2.kv")
screen=Manager()
screen.add_widget(Main(name="main"))

class Test(App):
    def build(self):
        return screen

Test().run()

Kv Code:

<Main>:
    name: "main"
    FloatLayout:
        id: Fl2
        Button:
            id: counter1
            text: "Counter"
            size_hint: (.25,.1)
            pos_hint: {"center_x":.5,"center_y":.3}
            on_press:
                root.counter(self) # this should count no. of buttons that are ON i.e. the selected buttons
        ToggleButton:
            id: Seat_A2
            color: (0,0,0,0)
            text: "Seat_A2"
            size_hint: (.0225,.0120)
            pos_hint: {"center_x":.4,"center_y":.75}
            background_color: (1,1,1,1)
            on_state:
                root.count(self) #i'm not sure if this func needs to be called individually 
on all the toggle buttons or just one func in the counter button (i.e. root.counter(self))... idk the method... 

        ToggleButton:
            id: Seat_A3
            color: (0,0,0,0)
            text: "Seat_A3"
            size_hint: (.0225,.0120)
            pos_hint: {"center_x":.4225,"center_y":.75}
            background_color: (1,1,1,1)
            on_state:
                root.count(self)

        ToggleButton:
            id: Seat_A6
            color: (0,0,0,0)
            text: "Seat_A6"
            size_hint: (.0225,.0120)
            pos_hint: {"center_x":.4900,"center_y":.75}
            background_color: (1,1,1,1)
            on_state:
                root.count(self)

        ToggleButton:
            id: Seat_A7
            color: (0,0,0,0)
            text: "Seat_A7"
            size_hint: (.0225,.0120)
            pos_hint: {"center_x":.5120,"center_y":.75}
            background_color: (1,1,1,1)
            on_state:
                root.count(self)


        ToggleButton:
            id: Seat_A10
            color: (0,0,0,0)
            text: "Seat_A10"
            size_hint: (.0225,.0120)
            pos_hint: {"center_x":.5800,"center_y":.75}
            background_color: (1,1,1,1)
            on_state:
                root.count(self)

        ToggleButton:
            id: Seat_A11
            color: (0,0,0,0)
            text: "Seat_A11"
            size_hint: (.0225,.0120)
            pos_hint: {"center_x":.6025,"center_y":.75}
            background_color: (1,1,1,1)
            on_state:
                root.count(self)

Answer 1

You can process the children of the FloatLayout that contains the ToggleButtons, like this:

def counter(self,widget):
    toggles = []
    for child in self.ids.Fl2.children:
        if isinstance(child, ToggleButton):
            if child.state == 'down':
                toggles.append(child.text)
    print(len(toggles), 'ToggleeButtons active:', toggles)