How do I use a variable from a text input as the text for a Label (kivy)

Question

I was brainstorming an idea I had for a project but the one part I got stuck at was collecting a variable from a text input box and displaying its Value as a Label in another screen, I tried putting it in a variable then just calling it as the text for the label in the kivy file but it always came back as an error, what am I doing wrong.

Kivy-

WindowManager:
    Enter_Name
    List


<Enter_Name>
    airline: input_1
    name: 'enter_name'
    id: enter_nom
    FloatLayout:
        cols: 3
        size: root.size
        Label:
            text: "Name of Airline?"
            size_hint: 1, 0.3
            pos_hint: {"x": 0, "top":1}

        TextInput:
            multiline: False
            name: 'input_one'
            id: input_1
            size_hint: 0.6, 0.06
            pos_hint: {"x": 0.20, "top":0.6}
        Button:
            size_hint: 0.2, 0.1
            pos_hint: {"x": 0.4, "top":0.4}
            text: "Enter"
            on_release: 
                app.root.current = 'list'
                root.line()

<List>
    name: 'list'

Python -

import kivy
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.floatlayout import FloatLayout
from kivy.properties import ObjectProperty
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.uix.textinput import TextInput
from kivy.uix.label import Label
from kivy.lang import Builder
from kivy.uix.popup import Popup
import time
from kivy.properties import StringProperty

class Enter_Name(Screen):
    input_1 = StringProperty()
    def line(self):
        self.gon = self.ids.input_1.text
        print(self.gon)    
    pass

class List(Screen):
    Enter_Name.line
    pass

class WindowManager(ScreenManager):
    pass

kv = Builder.load_file("pot.kv")

class am4(App):
    def build(self):
        return kv


if __name__ == "__main__":
    am4().run()

Answer 1

Here is a modified version of your code that does what I think you want:

from kivy.app import App
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.lang import Builder

class Enter_Name(Screen):
    def line(self):
        App.get_running_app().root.get_screen('list').lab_text = self.airline.text

class List(Screen):
    pass

class WindowManager(ScreenManager):
    pass

# kv = Builder.load_file("pot.kv")
kv = Builder.load_string('''
WindowManager:
    Enter_Name
    List


<Enter_Name>
    airline: input_1
    name: 'enter_name'
    id: enter_nom
    FloatLayout:
        cols: 3
        size: root.size
        Label:
            text: "Name of Airline?"
            size_hint: 1, 0.3
            pos_hint: {"x": 0, "top":1}

        TextInput:
            multiline: False
            name: 'input_one'
            id: input_1
            size_hint: 0.6, 0.06
            pos_hint: {"x": 0.20, "top":0.6}
        Button:
            size_hint: 0.2, 0.1
            pos_hint: {"x": 0.4, "top":0.4}
            text: "Enter"
            on_release: 
                app.root.current = 'list'
                root.line()

<List>
    lab_text: ''
    name: 'list'
    Label:
        text: root.lab_text
''')

class am4(App):
    def build(self):
        return kv


if __name__ == "__main__":
    am4().run()

I have added a Label to the List Screen , as well as a lab_text property that is used as the text of the Label . The line() method now just sets the value of that lab_text .

I have used load_string() instead of load_file() just for my own convenience.