我收到一条错误，上面写着“阴影名称'从外部范围运行'”，我该如何解决？：
print("Logic Gate Calculator")
def AND(a, b): # AND Gate
a = int(a)
b = int(b)
if a == 1 and b == 1: # AND Gate logic
return 1
else:
return 0
def NAND(a, b): # NAND Gate
a = int(a)
b = int(b)
if a == 1 and b == 1: # NAND Gate logic
return 0
elif a == 1 and b == 0:
return 0
elif a == 0 and b == 1:
return 0
else:
return 1
def OR(a, b): # OR Gate
a = int(a)
b = int(b)
if a == 1: # OR Gate Logic
return 1
elif b == 1:
return 1
else:
return 0
def NOR(a, b): # NOR Gate
a = int(a)
b = int(b)
if a == 1 and b == 0: # NOR Gate Logic
return 1
elif a == 0 and b == 1:
return 1
elif a == 0 and b == 0:
return 1
else:
return 0
run = True
while run:
def main(): # The main program
run = True # This extra run = True allows use to quit the program
question = input("What type of gate do you want to use OR, AND, NOR, or NAND or (Q)uit") # Logic Gate chooser
if question == "AND" or question == "and" or question == "And": # If the user selects AND
a = input("Enter value for input 1 (1 or 0):") # Getting the Logic Gate's 1st input
b = input("Enter value for input 2 (1 or 0):") # Getting the Logic Gate's 2nd input
x = AND(a, b) # Calling the AND Function
print(x)
elif question == "OR" or question == "or" or question == "Or": # If the user selects OR
a = input("Enter value for input 1 (1 or 0):") # Getting the Logic Gate's 1st input
b = input("Enter value for input 2 (1 or 0):") # Getting the Logic Gate's 2nd input
x = OR(a, b) # Calling the OR Function
print(x)
elif question == "NOR" or question == "nor" or question == "Nor": # If the user selects NOR
a = input("Enter value for input 1 (1 or 0):") # Getting the Logic Gate's 1st input
b = input("Enter value for input 2 (1 or 0):") # Getting the Logic Gate's 2nd input
x = NOR(a, b) # Calling the NOR function
print(x)
elif question == "NAND" or question == "nand" or question == "Nand": # If the user selects NAND
a = input("Enter value for input 1 (1 or 0):") # Getting the Logic Gate's 1st input
b = input("Enter value for input 2 (1 or 0):") # Getting the Logic Gate's 2nd input
x = NAND(a, b) # Calling the NAND function
print(x)
elif question == "Q" or question == "q": # Quiting the program
run = False
else:
print("Please enter one of the shown logic gates") # Error handling
main()