未在python中定义的函数内定义值

Question

嗨，我目前正在学习python，只是尝试了一些东西

# Import module
import random
random.seed()

# (Random) values and calculation
firstValue = random.randint(1,10)
secondValue = random.randint(1,10)
sol = firstValue + secondValue

# Define function called in try section of while-loop
def getUserInput():
    print("--- Please solve:", firstValue, "+", secondValue, "---")
    playerSol = input()
    playerSolInt = int(playerSol)

counter = 0
falseAnswer = True

while falseAnswer:
    counter += 1
    try:
       getUserInput()
    except: 
        print("--- You did not enter a number. ---")
        continue

    if sol == playerSolInt:
        print("--- Correct answer! ---")
        falseAnswer = False
    else:
        print("--- False answer! ---")

print("--- You tried", counter, "times in total. ---")
print("*** Program has stopped ***")

getUserInput（）的函数内容主要是在try中调用函数的地方：。。。现在，当我定义函数时，它告诉我playerSolInt没有定义。在IDE中，以及在终端中调用函数时，它会在异常中解析。在程序开始时用0初始化变量不会改变任何内容

那么，这是怎么回事？这可能是一件简单的事情，因为缺乏知识，我无法动脑

先谢谢大家😬

Answer 1

看看这个关于Python Scoping的教程

A variable created inside a function belongs to the local scope of that function, and can only be used inside that function.

您的playerSolInt变量在函数外部不可用，因此需要从函数返回它并在外部赋值

# Import module
import random
random.seed()

# (Random) values and calculation
firstValue = random.randint(1,10)
secondValue = random.randint(1,10)
sol = firstValue + secondValue

# Define function called in try section of while-loop
def getUserInput():
    print(" - Please solve:", firstValue, "+", secondValue, " -")
    playerSol = input()
    return int(playerSol) # this will return it
    

counter = 0
falseAnswer = True

while falseAnswer:
    counter += 1
    try:
       playerSolInt = getUserInput() # this will assign the returned value
    except: 
        print(" - You did not enter a number.  -")
        continue

    if sol == playerSolInt: 
        print(" - Correct answer!  -")
        falseAnswer = False
    else:
        print(" - False answer!  -")

print(" - You tried", counter, "times in total.  -")
print("*** Program has stopped ***")

Answer 2

变量playerSolInt是函数getUserInput的局部变量。你需要让它全球化。以下代码工作：

# Import module
import random
random.seed()

# (Random) values and calculation
firstValue = random.randint(1,10)
secondValue = random.randint(1,10)
sol = firstValue + secondValue

# Define function called in try section of while-loop
def getUserInput():
    print(" - Please solve:", firstValue, "+", secondValue, " -")
    playerSol = input()
    global playerSolInt
    playerSolInt = int(playerSol)

counter = 0
falseAnswer = True

while falseAnswer:
    counter += 1
    try:
       getUserInput()
    except: 
        print(" - You did not enter a number.  -")
        continue

    if sol == playerSolInt:
        print(" - Correct answer!  -")
        falseAnswer = False
    else:
        print(" - False answer!  -")

print(" - You tried", counter, "times in total.  -")
print("*** Program has stopped ***")