Kivy 和 Python TypeError: object.__init__() 只接受一个参数（要初始化的实例）

Question

我在其他 kivy 文件中有两个文件，如下所示。运行主文件时，出现以下错误：

File "C:\Users\JeffO\OneDrive\Desktop\Gym App\workoutbanner.py", line 13, in __init__
    super(WorkoutBanner, self).__init__(**kwargs)
  File "C:\Users\JeffO\anaconda3\lib\site-packages\kivy\uix\gridlayout.py", line 279, in __init__
    super(GridLayout, self).__init__(**kwargs)
  File "C:\Users\JeffO\anaconda3\lib\site-packages\kivy\uix\layout.py", line 76, in __init__
    super(Layout, self).__init__(**kwargs)
  File "C:\Users\JeffO\anaconda3\lib\site-packages\kivy\uix\widget.py", line 350, in __init__
    super(Widget, self).__init__(**kwargs)
  File "kivy\_event.pyx", line 245, in kivy._event.EventDispatcher.__init__
TypeError: object.__init__() takes exactly one argument (the instance to initialize)

你能帮我找出问题所在吗？我期待在主屏幕上获得个人资料图片。我怀疑第二个文件中的 left_image 会导致问题，但我不确定。

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import Screen
from kivy.uix.button import ButtonBehavior
from kivy.uix.image import Image
import requests
import json
from workoutbanner import WorkoutBanner


class HomeScreen(Screen):
    pass
class ImageButton(ButtonBehavior,Image):
    pass

class SigninScreen(Screen):
    pass

GUI = Builder.load_file("main.kv")

class MainApp(App):
    my_user_id = 'user1'
    user_table = "users"
    activity_table = "activities"
    def build(self):
        return GUI
    
    def on_start(self):
        #Query database data
        result_users = requests.get("https://uniquedatabase-c4647-default-rtdb.firebaseio.com/" + self.user_table + ".json")
        result_activities = requests.get("https://uniquedatabase-c4647-default-rtdb.firebaseio.com/" + self.activity_table + ".json")
        data_users = json.loads(result_users.content.decode())
        data_activities = json.loads(result_activities.content.decode())
        
        streak_label = self.root.ids['home_screen'].ids['streak_label']
        streak_label.text = str(data_users[self.my_user_id]['streak'])
        
        banner_grid = self.root.ids['home_screen'].ids['banner_grid']
        for workouts in data_activities.values():
            W = WorkoutBanner(user=workouts['user'])
            banner_grid.add_widget(W)
            
        
        #Fill HomeScreen feed
    def change_screen(self,screen_name):
        screen_manager = self.root.ids["screen_manager"]
        screen_manager.current = screen_name
        
MainApp().run()

from kivy.uix.gridlayout import GridLayout 
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.image import Image
from kivy.uix.label import Label
from firebase_functions import get_profile_picture
from datetime import datetime

class WorkoutBanner(GridLayout):
    
    rows = 1
  
    def __init__(self,**kwargs):
        super(WorkoutBanner, self).__init__(**kwargs)
      
        left = FloatLayout()
        left_image = Image(source= "images/" + kwargs['user'], 
        size_hint =(1,0.8), pos_hint={"top":1,"left":1})
        
        left.add_widget(left_image)
        
        self.add_widget(left)

Answer 1

代码行：

W = WorkoutBanner(user=workouts['user'])

正在为WorkoutBanner 提供一个kwargs 参数，但WorkoutBanner 的__init__() 方法无法处理kwarg。结果，kwargs 被传递给super：

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

然后又将kwargs 传递给它的super。以此类推，直到它到达导致异常的EventDispatcher.__init__()。

我相信您可以通过将Property 添加到WorkoutBanner 的user 属性来解决此问题：

class WorkoutBanner(GridLayout):
    rows = 1
    user = StringProperty('')

这假定user 是String。

Answer 2

初始化程序得到了意外的关键字参数 (https://github.com/kivy/kivy/issues/3650#issuecomment-148154997)