TypeError: __init__() takes 1 positional argument but 2 were given

[Jeremy Donahue]

New Kivy user.

Currently working through the following documentation.

https://buildmedia.readthedocs.org/media/pdf/kivy/latest/kivy.pdf

Attempting to run the code on page 36.

from kivy.app import App

from kivy.uix.label import Label

from kivy.uix.gridlayout import GridLayout

from kivy.uix.textinput import TextInput

class LoginScreen(GridLayout):

    def __init__(self, **kwargs):

        super(LoginScreen, self).__init__(**kwargs)

        self.cols = 2

        self.add_widget(Label('User Name:'))

        self.username = TextInput(multiline=False)

        self.add_widget(self.username)

        self.add_widget(Label('Password:'))

        self.password = TextInput(password=True, multiline=False)

        self.add_widget(self.password)

class MyApp(App):

    def build(self):

        return LoginScreen()

if __name__ == '__main__':

    MyApp().run()

I receive the following error.

I do not understand what it won't run.

As far as I can tell my code is exactly like the code in the guide.

(tut) Jeremys-MacBook-Pro:tut home$ python my.py

[INFO   ] [Logger      ] Record log in /Users/home/.kivy/logs/kivy_20-04-20_0.txt

[INFO   ] [Kivy        ] v1.11.1

[INFO   ] [Kivy        ] Installed at "/Users/home/Documents/python-virtual-environments/tut/lib/python3.7/site-packages/kivy/__init__.py"

[INFO   ] [Python      ] v3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 16:52:21) 

[Clang 6.0 (clang-600.0.57)]

[INFO   ] [Python      ] Interpreter at "/Users/home/Documents/python-virtual-environments/tut/bin/python"

[INFO   ] [Factory     ] 184 symbols loaded

[INFO   ] [Image       ] Providers: img_tex, img_imageio, img_dds, img_sdl2, img_gif (img_pil, img_ffpyplayer ignored)

[INFO   ] [Text        ] Provider: sdl2

[INFO   ] [Window      ] Provider: sdl2

[INFO   ] [GL          ] Using the "OpenGL ES 2" graphics system

[INFO   ] [GL          ] Backend used <sdl2>

[INFO   ] [GL          ] OpenGL version <b'2.1 INTEL-12.10.14'>

[INFO   ] [GL          ] OpenGL vendor <b'Intel Inc.'>

[INFO   ] [GL          ] OpenGL renderer <b'Intel Iris OpenGL Engine'>

[INFO   ] [GL          ] OpenGL parsed version: 2, 1

[INFO   ] [GL          ] Shading version <b'1.20'>

[INFO   ] [GL          ] Texture max size <16384>

[INFO   ] [GL          ] Texture max units <16>

[INFO   ] [Window      ] auto add sdl2 input provider

[INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked

 Traceback (most recent call last):

   File "my.py", line 24, in <module>

     MyApp().run()

   File "/Users/home/Documents/python-virtual-environments/tut/lib/python3.7/site-packages/kivy/app.py", line 829, in run

     root = self.build()

   File "my.py", line 20, in build

     return LoginScreen()

   File "my.py", line 10, in __init__

     self.add_widget(Label('User Name:'))

 TypeError: __init__() takes 1 positional argument but 2 were given

[Robert Flatt]

Use:

Label(text="whatever")

Because:

1) this is Object Oriented Programming , there is an implicit     self    as the first positional argument  - that is the 1 positional argument

2) Label only takes one positional argument, the  (optional) other arguments use named association - by just specifying "whatever" you created a second positional argument.

Hence the error expected 1 positional argument but 2 were given.

So use named association for the text value

[Jeremy Donahue]

Thank you.