【问题标题】：Name 'x' is not defined / Global variable?名称“x”未定义/全局变量？
【发布时间】：2019-09-28 02:29:41
【问题描述】：

我正在学习使用 python 编程，但遇到了这个问题：我正在尝试制作一个猜谜游戏，并且在尝试检查获胜条件时，该函数无法识别输入变量，我确保我返回了以前的函数。所以我得到 'name > 错误。我认为这与变量不是全局的或类似的东西有关。

import random
ran_int = random.randint(1,100)
guesses = 0

# here you input the number and it keeps asking unless you do so with 1 to 100

def ask():
    first_input = 0
    while first_input < 1 or first_input > 100:
        first_input = int(input('Enter a number between 1 and 100: '))
    return first_input

# this is just to increment the number of guesses stored for showing at the end # of the game

def guesses_inc():
    global guesses
    guesses += 1
    return guesses

# here is where i get the error, as if my ask() function didn't return 
# the value properly or as if I assigned it wrongly

def check_win_1():
    if first_input == ran_int:
        guesses_inc()
        print(f'BINGO!\nYou guessed correctly after {guesses} times.')
    elif (abs(ran_int - first_input) <= 10):
        guesses_inc()
        print('WARM!')
        ask2()
    elif first_input < 1 or first_input > 100:
        print('Out of bounds!')
        ask2()
    else:
        guesses_inc()
        print('COLD!')
        ask2()

ask()
check_win_1()

这是错误

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-11-bfd5497995df> in <module>
----> 1 check_win_1()

NameError: name 'first_input' is not defined

我没有粘贴整个代码，因为在测试它时它在这个阶段返回了错误，所以我认为其余的对于这个特定的问题并不重要。我尝试将 var 输入设为全局和类似的东西，但我认为我做得不对。

【问题讨论】：

你可能在最后一行check_win_1 后面缺少括号
你还没有定义ask2()方法

标签： python

【解决方案1】：

您的方法调用不正确。你应该像这样调用你的函数

def check_win_1(first_input):
    if first_input == ran_int:
        guesses_inc()
        print(f'BINGO!\nYou guessed correctly after {guesses} times.')
    elif (abs(ran_int - first_input) <= 10):
        guesses_inc()
        print('WARM!')
        ask2()
    elif first_input < 1 or first_input > 100:
        print('Out of bounds!')
        ask2()
    else:
        guesses_inc()
        print('COLD!')
        ask2()
first_input = ask()
check_win_1(first_input)

【讨论】：

谢谢！效果很好！我没有存储函数返回的值，也没有在下一个参数上调用正确的参数

【解决方案2】：

出现错误是因为您试图在某处使用first_input（即在check_win_1() 内部）。

一种可能但不推荐的解决方案是将您的变量限定为global，应谨慎使用非常。

建议使用函数参数，以便将您的代码封装在独立的块中，例如：

def func(a, b):
    return a + b


x = func(10, 5)

而不是：

def func():
    global a, b
    return a + b

a = 10
b = 5

x = func()

对于您来说，这可能意味着执行以下操作：

def check_win_1(first_input, ran_int):
    ...

并相应地使用它们，例如：

first_input = ask()
check_win_1(first_input, ran_int)

等等

编辑

按照上述原则，您的代码可能如下所示：

import random

MIN_VAL = 1
MAX_VAL = 100
WARM_LIMIT = 10


def ask_number(
        min_val=MIN_VAL,
        max_val=MAX_VAL):
    guess = None
    while guess is None:
        guess = int(input(f'Enter a number between {min_val} and {max_val}: '))
        if guess < min_val or guess > max_val:
            print('Out of bounds!')
            guess = None
    return guess


def check_guess(
        guess,
        target,
        num_guesses,
        warm_limit=WARM_LIMIT):
    if guess == target:
        print(f'BINGO!\nYou guessed correctly after {num_guesses} times.')
        return True
    else:
        if (abs(guess - target) <= warm_limit):
            print('WARM!')
        else:
            print('COLD!')
        return False


# : main
target = random.randint(MIN_VAL, MAX_VAL)
num_guesses = 0
won = False
while not won:
    guess = ask_number()
    num_guesses += 1
    won = check_guess(guess, target, num_guesses)

【讨论】：