编写嵌套代码时出现未绑定的本地错误

Question

我正在尝试调整我的 python 上的子文件，但它不断向我显示前面引用的变量 (Min_Alpha) 上的 unboundlocalerror。 我对此感到困惑，就好像我运行 alpha 命令时我没有收到任何错误，但是当我运行 beta 命令时我收到此错误。 任何帮助将非常感激。

def main():
    
    print("Welcome to the Beta Distribution Software")
    print(" ")
    playerschoice = input("Do you want to use this software ? Yes/No : ")
    if (playerschoice == "yes" or playerschoice =="Yes" or playerschoice == "YES"):
        Body_function_01()
        
    else:
        end_program()

        
def Body_function_01():
    
    users_choice = input("What constant would you like to vary ? Alpha/Beta: ")
    if (users_choice == "Alpha" or users_choice == "alpha"):
        Max_Alpha = float(input("Enter the Maximum Alpha Value: "))
        Min_Alpha = float(input("Enter the Minimum Alpha Value: "))
        Alpha_increment = float(input("Enter Alpha Increment Value: "))
        Beta_constant = float(input("Enter constant Beta value"))  
    else:
        Body_function_02() 
        
    if (Min_Alpha >= 0):
        print("Minimum Alpha value is within an acceptable range")
    elif (Min_Alpha < 0):
        print("Minimum value of alpha is too low ")
        print ("Try again")
    if ((Max_Alpha - Min_Alpha) > Alpha_increment):
        print("The Alpha Increment is within an acceptable range")
    elif ((Max_Alpha - Min_Alpha) < Alpha_increment):
        print("The Alpha increment is too high")
        print("Try again")
    if (Max_Alpha > Min_Alpha):
        print("The Maximum value of alpha is within an acceptable range")
    elif (Max_Alpha < Min_Alpha):
        print("The maximum value of alpha is too high")
        print("Try again")
        
    
        
           
def Body_function_02():
        
    users_choice = input("What constant would you like to vary ? Alpha/Beta: ")
    if (users_choice == "Beta" or users_choice == "beta"):
        Max_Beta = float(input("Enter the Maximum Beta Value: "))
        Min_Beta = float(input("Enter the Minimum Beta Value: "))
        Beta_increment = float(input("Enter Beta Increment Value: "))
        Alpha_constraint = float(input("Enter constant Alpha value: "))
    
    else:
        print("Try again")
    
    if (Min_Beta >= 0):
        print("Minimum Beta value is within an acceptable range")
    elif (Min_Beta < 0):
        print("Minimum value of Beta is too low ")
        print ("Try again")
    if ((Max_Beta - Min_Beta) > Beta_increment):
        print("The Beta Increment is within an acceptable range")
    elif ((Max_Beta - Min_Beta) < Beta_increment):
        print("The Beta increment is too high")
        print("Try again")
    if (Max_Beta > Min_Beta):
        print("The Maximum value of Beta is within an acceptable range")
    elif (Max_Beta < Min_Beta):
        print("The maximum value of Beta is too high")
        print("Try again")
        

def end_program():
    print(" ")
    input("Press any key to leave")
    sys.exit()


main()   
Body_function_01()   
Body_function_02()
end_program().   



---------------------------------------------------------------------------
UnboundLocalError                         Traceback (most recent call last)
<ipython-input-25-c662d0a92b77> in <module>
    111 
    112 
--> 113 main()
    114 Body_function_01()
    115 Body_function_02()

<ipython-input-25-c662d0a92b77> in main()
     16     playerschoice = input("Do you want to use this software ? Yes/No : ")
     17     if (playerschoice == "yes" or playerschoice =="Yes" or playerschoice == "YES"):
---> 18         Body_function_01()
     19 
     20     else:

<ipython-input-25-c662d0a92b77> in Body_function_01()
     33         Body_function_02()
     34 
---> 35     if (Min_Alpha >= 0):
     36         print("Minimum Alpha value is within an acceptable range")
     37     elif (Min_Alpha < 0):

UnboundLocalError: local variable 'Min_Alpha' referenced before assignment

Answer 1

我认为问题在于Min_Alpha在以下情况下被初始化：

users_choice = input("What constant would you like to vary ? Alpha/Beta: ")
if (users_choice == "Alpha" or users_choice == "alpha"):
    Max_Alpha = float(input("Enter the Maximum Alpha Value: "))
    Min_Alpha = float(input("Enter the Minimum Alpha Value: "))
    Alpha_increment = float(input("Enter Alpha Increment Value: "))
    Beta_constant = float(input("Enter constant Beta value"))  

只有当用户选择 Alpha/alpha 时，它才会被初始化。 对于任何其他选择，变量将不会被初始化，并且当您将其与 0 进行比较时它将是无界的。不确定预期的行为是什么，但我认为您应该在Body_function_01和Body_function_02函数中return else情况。