KeyError：<class'__main __。STAGE1'>

Question

下面的代码显示了包含一系列页面的化学测验应用程序，用户可以在这些页面之间切换这些页面。

class STARTPAGE(tk.Frame): 
    def __init__(self, parent, controller): 
     tk.Frame.__init__(self, parent) 
     Instructions1 = tk.Label(self, text=("You will obtain a Desired Product that is chosen randomly from a Starting Reactant."))              
     Instructions2 = tk.Label(self, text=("You get 3 Attempts to complete the question in which Points will be added to your score ")) 
     Instructions3 = tk.Label(self, text=("After 3 attempts you will be moved onto next stage or question")) 
     Instructions4 = tk.Label(self, text=("You need to select one Reagent and 1 or 2 Conditions to complete stage")) 
     Instructions5 = tk.Label(self, text=("Your score will be ranked among others in your same class in a leaderboard")) 

     Instructions1.grid(row=0, column=0) 
     Instructions2.grid(row=1, column=0) 
     Instructions3.grid(row=2, column=0) 
     Instructions4.grid(row=3, column=0) 
     Instructions5.grid(row=4, column=0) 

     StartQuiz = tk.Button(self, text="Start Quiz", command=lambda: controller.show_frame(STAGE1)) 
     StartQuiz.grid(row=8, column=1) 

class STAGE1(tk.Frame): 
    def __init__(self, parent, controller): 
     tk.Frame.__init__(self, parent) 
     self.controller = controller 

     Stage1 = tk.Label(self, text="STAGE 1") 
     Stage1.grid(column=1, row=0)   
     #Explain the Main class and tk frame constructor in each class from stack overflow   
     self.ButtonData = BUTTONDATA(self, tk.Frame) 

     self.ButtonData.ReagentOption1.config(command=lambda: self.AllocatePointsStage(1)) 
     self.ButtonData.ReagentOption2.config(command=lambda: self.AllocatePointsStage(1)) 
     self.ButtonData.ReagentOption3.config(command=lambda: self.AllocatePointsStage(1)) 
     self.ButtonData.ReagentOption4.config(command=lambda: self.AllocatePointsStage(1)) 

     self.ButtonData.ConditionOption1.config(command=lambda: self.AllocatePointsStage(1)) 
     self.ButtonData.ConditionOption2.config(command=lambda: self.AllocatePointsStage(1)) 
     self.ButtonData.ConditionOption3.config(command=lambda: self.AllocatePointsStage(1)) 
     self.ButtonData.ConditionOption4.config(command=lambda: self.AllocatePointsStage(1)) 

     self.ButtonData.ReagentOption1.grid(column=2, row=5) 
     self.ButtonData.ReagentOption2.grid(column=2, row=6) 
     self.ButtonData.ReagentOption3.grid(column=2, row=7) 
     self.ButtonData.ReagentOption4.grid(column=2, row=8) 

     self.ButtonData.ConditionOption1.grid(column=10, row=5) 
     self.ButtonData.ConditionOption2.grid(column=10, row=6) 
     self.ButtonData.ConditionOption3.grid(column=10, row=7) 
     self.ButtonData.ConditionOption4.grid(column=10, row=8) 

     self.Continue = tk.Button(self, text="Continue", command=lambda: controller.show_frame(Stage2)) 
     self.Continue.grid(column=6) 

     self.QuestionStarter = QUESTIONSTARTER(self, tk.Frame) 
     self.QuestionStarter.PointsLabel.grid(row=0, column=6) 
     self.QuestionStarter.AttemptsDisplayed.grid(row=1, column=7) 
     self.QuestionStarter.WordedQuestion.grid(row=0, column=1) 
     self.QuestionStarter.AttemptsDisplayedText.grid(row=1, column=8) 
     DesiredProductLabel = tk.Label(self, command=lambda: ShowDesiredProduct(DesiredProduct)) 
     DesiredProductLabel.grid(row=5, column=0) 

    def ShowDesiredProduct(self, DesiredProduct): 
     DesiredProduct = GetDesiredProduct() 
     return DesiredProduct 

class Main(tk.Tk): 
    def __init__(self, *args, **kwargs): 
     tk.Tk.__init__(self, *args, **kwargs) 
     tk.Tk.wm_title(self, "Chemistry Quiz") 
     container = tk.Frame(self) 
     container.pack(side="top", fill="both", expand=True) 
     container.grid_rowconfigure(0, weight=1) 
     container.grid_columnconfigure(0, weight=1) 
     self.frames = {} 

     for F in (STUDENTLOGINPAGE, STAFFLOGINPAGE, STARTPAGE, ASSIGNMENTPAGE, STAGE1, STAGE2, STAGE3, STAGE4, STAGE5, LEADERBOARDPAGE): 

      frame = F(container, self) 

      self.frames[F] = frame 

      frame.grid(row=0, column=0, sticky="nsew") 

      self.show_frame(STUDENTLOGINPAGE) 
      if self.frames == []: 
       print ("Error in loading program") 
      #This class inherits from Tk class within module of Tk Inter 
      #This basically displays each page in turn from the List 

    def show_frame(self, cont): 
     frame = self.frames[cont] 
     frame.tkraise() 

    def get_page(self, page_class): 
     return self.frames[page_class] 

出于某种原因，我得到以下错误，其中我的节目框架内发生的第1阶段：

Error -Traceback (most recent call last): 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/tkinter/__init__.py", line 1549, in __call__ 
    return self.func(*args) 
    File "/Users/ammarhusain/Desktop/Computing Project/Ammar Chemistry Program FINAL.py", line 316, in <lambda> 
    StartQuiz = tk.Button(self, text = "Start Quiz", command=lambda: controller.show_frame(STAGE1)) 
    File "/Users/ammarhusain/Desktop/Computing Project/Ammar Chemistry Program FINAL.py", line 3152, in show_frame 
    frame = self.frames[cont] 
KeyError: <class '__main__.STAGE1'> 

Answer 1

这里的问题是，你正在使用的类定义为一个关键：

# add the frame 
self.frames[F] = frame 
# show the frame 
self.show_frame(STUDENTLOGINPAGE) 

我建议你使用字符串作为字典的关键，并移动这些线条勾勒出循环：

self.show_frame(STUDENTLOGINPAGE) 

现在回到你的堆栈跟踪，你有这一行有：

controller.show_frame(STAGE1) 

因此，控制器不包含该按钮被点击时STAGE1屏幕。如果显示正在创建的STUDENTLOGINPAGE后所有屏幕，这个问题应该走出去：

# create all the screens 
for F in (STUDENTLOGINPAGE, STAFFLOGINPAGE, STARTPAGE, ASSIGNMENTPAGE, STAGE1, STAGE2, STAGE3, STAGE4, STAGE5, LEADERBOARDPAGE): 
    frame = F(container, self) 
    self.frames[F] = frame 
    frame.grid(row=0, column=0, sticky="nsew") 

# check the sreens availability 
if self.frames == []: 
    print ("Error in loading program") 

# now show the login form 
self.show_frame(STUDENTLOGINPAGE)