Checking for an id as child of an instance class gives error
Question
So I have to get the id of the image existing inside the instance (button) so I have stored all the ids of the imgs in an array. There are 64 buttons and only 16 contain images so there is a total of 16 images in which all are different. Below is my half of my.kv code and my.py code.
<Game>:
name: "ChessBoard"
GridLayout:
id: chess_board
cols: 8
rows: 8
padding: ("60dp", "60dp", "60dp", "60dp")
orientation: 'tb-lr'
Button:
id: button_1
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
AsyncImage:
id: white_1
source: 'imgs/WhiteCastle.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_2
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
AsyncImage:
id: white_2
source: 'imgs/WhiteKnight.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_3
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
AsyncImage:
id: white_3
source: 'imgs/WhiteBishop.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_4
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
AsyncImage:
id: white_4
source: 'imgs/WhiteQueen.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_5
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
AsyncImage:
id: white_5
source: 'imgs/WhiteKing.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_6
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
AsyncImage:
id: white_6
source: 'imgs/WhiteBishop.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_7
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
AsyncImage:
id: white_7
source: 'imgs/WhiteKnight.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_8
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
AsyncImage:
id: white_8
source: 'imgs/WhiteCastle.png'
center_x: self.parent.center_x
center_y: self.parent.center_y #8
Button:
id: button_9
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
AsyncImage:
id: white_9
source: 'imgs/WhitePawn.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_10
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
AsyncImage:
id: white_10
source: 'imgs/WhitePawn.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_11
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
AsyncImage:
id: white_11
source: 'imgs/WhitePawn.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_12
background_normal: ''
background_color: (1,1,1,1)
on_press:root.moves(self, root)
AsyncImage:
id: white_12
source: 'imgs/WhitePawn.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_13
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
AsyncImage:
id: white_13
source: 'imgs/WhitePawn.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_14
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
AsyncImage:
id: white_14
source: 'imgs/WhitePawn.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_15
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
AsyncImage:
id: white_15
source: 'imgs/WhitePawn.png'
center_x: self.parent.center_x
center_y: self.parent.center_y
Button:
id: button_16
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
AsyncImage:
id: white_16
source: 'imgs/WhitePawn.png'
center_x: self.parent.center_x
center_y: self.parent.center_y #16
Button:
id: button_17
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
Button:
id: button_18
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
Button:
id: button_19
background_normal: ''
background_color: (1,1,1,1)
on_press:root.moves(self, root)
Button:
id: button_20
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
Button:
id: button_21
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
Button:
id: button_22
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
Button:
id: button_23
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
Button:
id: button_24
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
Button:
id: button_25
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
Button:
id: button_26
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
Button:
id: button_27
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
Button:
id: button_28
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
Button:
id: button_29
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
Button:
id: button_30
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
Button:
id: button_31
background_color: (0, 0, 0, 1)
on_press: root.moves(self, root)
Button:
id: button_32
background_normal: ''
background_color: (1,1,1,1)
on_press: root.moves(self, root)
Now.py:
class Game(Screen):
def __init__(self, **kwargs):
super().__init__(**kwargs)
def img_list(self):
img_ids_list = []
for x in range(1, 17):
img_ids_list.append(f"white_{x}")
for y in range(1, 17):
img_ids_list.append(f"black_{y}")
return img_ids_list
def moves(self, instance, root):
all_ids = root.ids
id_of_button = self.get_id(instance)
img_id = self.check_if_img_exists(instance, root)
def check_if_img_exists(self, instance, root):
img_ids = self.img_list()
if img_ids[0] in root.ids:
print("Ready for launch!")
for x in range(1, 32):
asyncImage = root.ids.img_ids[x]
if asyncImage in instance.children:
print("Button contains an AsyncImage")
return asyncImage
print("Button does not contain an AsyncImage")
def get_id(self, instance):
for id, widget in instance.parent.parent.ids.items():
if widget.__self__ == instance:
return id
The error I get is
Traceback (most recent call last):
File "kivy\properties.pyx", line 961, in kivy.properties.ObservableDict.__getattr__
KeyError: 'img_ids'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\Zaviyar Zahid\kivy-thelab\venv\main.py", line 98, in <module>
ChessApp().run()
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\app.py",
line 955, in run
runTouchApp()
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\base.py", line 574, in runTouchApp
EventLoop.mainloop()
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\base.py", line 339, in mainloop
self.idle()
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\base.py", line 383, in idle
self.dispatch_input()
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\base.py", line 334, in dispatch_input
post_dispatch_input(*pop(0))
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\base.py", line 263, in post_dispatch_input
listener.dispatch('on_motion', etype, me)
File "kivy\_event.pyx", line 731, in kivy._event.EventDispatcher.dispatch
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\core\window\__init__.py", line 1660, in on_motion
self.dispatch('on_touch_down', me)
File "kivy\_event.pyx", line 731, in kivy._event.EventDispatcher.dispatch
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\core\window\__init__.py", line 1677, in on_touch_down
if w.dispatch('on_touch_down', touch):
File "kivy\_event.pyx", line 731, in kivy._event.EventDispatcher.dispatch
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\uix\screenmanager.py", line 1210, in on_touch_down
return super(ScreenManager, self).on_touch_down(touch)
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\uix\widget.py", line 589, in on_touch_down
if child.dispatch('on_touch_down', touch):
File "kivy\_event.pyx", line 731, in kivy._event.EventDispatcher.dispatch
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\uix\relativelayout.py", line 306, in on_touch_down
ret = super(RelativeLayout, self).on_touch_down(touch)
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\uix\widget.py", line 589, in on_touch_down
if child.dispatch('on_touch_down', touch):
File "kivy\_event.pyx", line 731, in kivy._event.EventDispatcher.dispatch
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\uix\widget.py", line 589, in on_touch_down
if child.dispatch('on_touch_down', touch):
File "kivy\_event.pyx", line 731, in kivy._event.EventDispatcher.dispatch
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\uix\behaviors\button.py", line 151, in on_touch_down
self.dispatch('on_press')
File "kivy\_event.pyx", line 727, in kivy._event.EventDispatcher.dispatch
File "kivy\_event.pyx", line 1307, in kivy._event.EventObservers.dispatch
File "kivy\_event.pyx", line 1191, in kivy._event.EventObservers._dispatch
File "C:\Users\Zaviyar Zahid\AppData\Roaming\Python\Python310\site-
packages\kivy\lang\builder.py", line 55, in custom_callback
exec(__kvlang__.co_value, idmap)
File "C:\Users\Zaviyar Zahid\kivy-thelab\venv\chess.kv", line 122, in <module>
on_press: root.moves(self, root)
File "C:\Users\Zaviyar Zahid\kivy-thelab\venv\main.py", line 49, in moves
img_id = self.check_if_img_exists(instance, root)
File "C:\Users\Zaviyar Zahid\kivy-thelab\venv\main.py", line 57, in check_if_img_exists
asyncImage = root.ids.img_ids[x]
File "kivy\properties.pyx", line 964, in kivy.properties.ObservableDict.__getattr__
AttributeError: 'super' object has no attribute '__getattr__'
1 answers
solution1
0 2022-07-24 13:21:03
If you look at the error message, it is complaining about the line:
asyncImage = root.ids.img_ids[x]
Since root is your Game instance, that code is trying to access an id named img_ids in the Game instance. But you have not defined an img_ids in your kv . I suspect that you actually intended to use the img_ids variable that you created in the check_if_img_exists() method. Try changing the above line to:
asyncImage = img_ids[x]
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