Include and use external Kv files in Python Kivy

Overview

I tried to test a basic application that imports an external Kv file using Include.

environment

OS: Windows10 64bit
Kivy:1.9.1
Python3.5

point

--Includes Kv files saved in a folder one level below --Redefine the properties in the external Kv file as RootWidget properties --Associate the method in RootWidget with the on_press property in the external Kv file

File placement

project-root
|-- main.py
|-- test.kv
`-- gui/
    `-- tab_test.kv

The code is as follows.

main.py

`main.py`


from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty

class RootWidget(BoxLayout):
    
    #Button defined in the Kv file_Define include Widget in Python file
    button_include = ObjectProperty()  
    
    def print_obj(self, obj):
        print(obj)
        
    def check_button_include(self):
        print(self.button_include)  #Access widget classes in external Kv files from within a Python file

class TestApp(App):
    def build(self):
        return RootWidget()


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

Kv file containing Root Widget

`test.kv`


#:include gui/tab_test.kv  #Import an external Kv file

<RootWidget>:
    # button_Define include as a property of RootWidget
    button_include: tab_button_include.button_include

    TabbedPanel:
        do_default_tab: False
        
        TabbedPanelItem:
            text: 'Tab1'
            BoxLayout:
                Button:
                    text: 'button 1'
                    on_press: root.print_obj(self)
                Button:
                    text: 'button 2'
                    on_press: root.check_button_include()
        TabbedPanelItem:
            text: 'Tab2'
            ButtonInclude:  #Use the widget class defined in the external Kv file
                id: tab_button_include  #Assign id to the defined widget class

External Kv file

`tab_test.kv`


<ButtonInclude@Button>:
    button_include: button_include

    id: button_include
    text: 'button include'
    on_press: app.root.print_obj(self)  # "app.root.method"Execute the RootWidget method from within the external Kv file with

Execution result

Operation result of each button

Button1          ->   <kivy.uix.button.Button object at 0x000001E0A8DE18D0>
Button2          ->   <kivy.factory.ButtonInclude object at 0x000001E0A8DE1A08>
Button include   ->   <kivy.factory.ButtonInclude object at 0x000001E0A8DE1A08>

reference

[Kivy Language — Kivy 1.9.2.dev0 documentation] (https://kivy.org/docs/api-kivy.lang.html#include-file) -How to use Python Kivy (reference) -I translated Kivy Language of API reference--- Qiita