kivy：動的に生成されるラベルのラベルテキストを変更する

Question

最後に、labels.textにセンサーデータが表示されます。データは別のプロセスで生成され、パイプ経由でkivyに転送されます。現在、私は非常に単純な最小限の例を実装しようとしています。しかし、私は、動的に生成されたラベルの更新コンセプトを中心に私の頭を得ることはありません：

from math import sin 

""" 
Activate the touch keyboard. It is important that this part is on top 
because the global config should be initiated first. 
""" 
from kivy.config import Config 
Config.set('kivy', 'keyboard_mode', 'multi') 

from kivy.app import App 

from kivy.clock import Clock 
# The Builder is used to define the main interface. 
from kivy.lang import Builder 

from kivy.properties import StringProperty, ObjectProperty, NumericProperty 
from kivy.uix.label import Label 
from kivy.uix.screenmanager import ScreenManager, Screen 
from kivy.uix.stacklayout import StackLayout 


import numpy as np 

class MainScreen(Screen): 
    pass 


class DataScreen(Screen): 

    def __init__(self, **kwargs): 
     layout = StackLayout() 
     super(DataScreen, self).__init__(**kwargs) 
     self.n_probes = 8 
     self.label_text = [] 
     for i in range(self.n_probes): 
      self.label_text.append(StringProperty()) 
      self.label_text[i] = str(i) 

     for i in range(self.n_probes): 
      l = Label(id='l_{}'.format(i), 
         name='l_{}'.format(i), 
         text=self.label_text[i], 
         font_size='60sp', 
         height=20, 
         width=20, 
         size_hint=(0.5, 0.2)) 
      self.ids.stack.add_widget(l) 

    def change_text(self): 
     for i in range(self.n_probes): 
      self.label_text[i] = str(2) 



Builder.load_file('phapp.kv') 

class MyApp(App): 
    """ 
    The settings App is the main app of the pHBot application. 
    It is initiated by kivy and contains the functions defining the main interface. 
    """ 


    def build(self): 
     """ 
     This function initializes the app interface and has to be called "build(self)". 
     It returns the user interface defined by the Builder. 
     """ 

     sm = ScreenManager() 
     sm.add_widget(MainScreen()) 
     sm.add_widget(DataScreen()) 
     # returns the user interface defined by the Builder 
     return sm 


if __name__ == '__main__': 
    MyApp().run() 

.kvファイル：

<MainScreen>: 
    name: 'main' 
    BoxLayout: 
     orientation: 'vertical' 
     Button: 
      text: 'Go to data' 
      font_size: 40 
      on_release: app.root.current = 'data' 
     Button: 
      text: 'Exit' 
      font_size: 40 
      on_release: app.stop() 

<DataScreen>: 
    name: 'data' 
    StackLayout: 
     id: stack 
     orientation: 'lr-tb' 
    BoxLayout: 
     Button: 
      size_hint: (0.5, 0.1) 
      text: 'Update' 
      font_size: 30 
      on_release: root.change_text() 
     Button: 
      size_hint: (0.5, 0.1) 
      text: 'Back to main menu' 
      font_size: 30 
      on_release: app.root.current = 'main' 

ラベルは、このバージョンに更新されていません。なぜどんなアイデア？

Answer 1

このバージョンは機能しています。私はまだ最初のものがうまくいかなかった理由はまだありません。多分それは範囲と何かにする必要がありますか？ .kvファイルと.pyファイル（たとえば、SO postのように）に静的にすべてを記述すると、すべて正常に動作します。

from math import sin 

""" 
Activate the touch keyboard. It is important that this part is on top 
because the global config should be initiated first. 
""" 
from kivy.config import Config 
Config.set('kivy', 'keyboard_mode', 'multi') 

from kivy.app import App 

from kivy.clock import Clock 
# The Builder is used to define the main interface. 
from kivy.lang import Builder 

from kivy.properties import StringProperty, ObjectProperty, NumericProperty 
from kivy.uix.label import Label 
from kivy.uix.screenmanager import ScreenManager, Screen 
from kivy.uix.stacklayout import StackLayout 


import numpy as np 

class MainScreen(Screen): 
    pass 


class DataScreen(Screen): 

    def __init__(self, **kwargs): 
     layout = StackLayout() 
     super(DataScreen, self).__init__(**kwargs) 
     self.n_probes = 8 
     self.label_text = [] 
     for i in range(self.n_probes): 
      self.label_text.append(StringProperty()) 
      self.label_text[i] = str(i) 
     self.l = [] 
     for i in range(self.n_probes): 
      self.l.append(Label(id='l_{}'.format(i), 
          text='Start {}'.format(i), 
          font_size='60sp', 
          height=20, 
          width=20, 
          size_hint=(0.5, 0.2))) 
      self.ids.stack.add_widget(self.l[i]) 

    def change_text(self): 
     for i in range(self.n_probes): 
      self.l[i].text = 'Update' + str(2) 


Builder.load_file('phapp.kv') 

class MyApp(App): 
    """ 
    The settings App is the main app of the pHBot application. 
    It is initiated by kivy and contains the functions defining the main interface. 
    """ 


    def build(self): 
     """ 
     This function initializes the app interface and has to be called "build(self)". 
     It returns the user interface defined by the Builder. 
     """ 

     sm = ScreenManager() 
     sm.add_widget(MainScreen()) 
     sm.add_widget(DataScreen()) 
     # returns the user interface defined by the Builder 
     return sm 


if __name__ == '__main__': 
    MyApp().run() 


<MainScreen>: 
    name: 'main' 
    BoxLayout: 
     orientation: 'vertical' 
     Button: 
      text: 'Go to data' 
      font_size: 40 
      on_release: app.root.current = 'data' 
     Button: 
      text: 'Exit' 
      font_size: 40 
      on_release: app.stop() 

<DataScreen>: 
    name: 'data' 
    StackLayout: 
     id: stack 
     orientation: 'lr-tb' 
    BoxLayout: 
     Button: 
      size_hint: (0.5, 0.1) 
      text: 'Update' 
      font_size: 30 
      on_release: root.change_text() 
     Button: 
      size_hint: (0.5, 0.1) 
      text: 'Back to main menu' 
      font_size: 30 
      on_release: app.root.current = 'main'