Still running… in multiple files, with global font_size…

main.py

@@ -1,23 +1,14 @@
-from random import randint
-
 from kivy.app import App
-from kivy.uix.boxlayout import BoxLayout
-
-
-class RanNum(BoxLayout):
-    pass
+from kivy.properties import NumericProperty
+from rannum import RanNum
 
 
 class RanKivApp(App):
-    def build(self):
-        return RanNum()
+    font_size = NumericProperty(24)
 
-    def generate_random_number(self):
-        try:
-            upper_boundary = int(self.root.ids.upper_boundary_input.text)
-            self.root.ids.output.text = str(randint(1, upper_boundary))
-        except ValueError:
-            self.root.ids.output.text = 'Bitte nur positive,\nganze Zahlen eingeben!'
+    def build(self):
+        self.ran_num = RanNum()
+        return self.ran_num
 
 
 if __name__ == '__main__':