Python开发[类型错误]

我是一个初学者，最近开始了python开发。 我正在编写的代码：

import random 
import textwrap

def show_message(dotted_line,width):

    print(dotted_line)
    print("\033[1m"+ "Attack of clones:" + "\033[0m")

    message = (
    "The war between humans and their arch enemies , Clones was in the offing. Obi-Wan, one of the brave Jedi on his way ," 
    "he spotted a small isolted settlement .Tired and hoping to replenish his food stock , he decided to take a detour." 
    "As he approached the village, he saw five residence , there was no one to be seen around.He decided to enter" )
    print(textwrap.fill(message, width = width))

def show_mission(dotted_line):
    print("\033[1m"+ "Mission:" + "\033[0m")
    print('\t Choose the hit where Obi wan can rest...')
    print("\033[1m"+ "TIP:" + "\033[0m")
    print("Be careful as there are Stormtroopers lurking around!")
    print(dotted_line)


def occupy_huts():
    global huts
    huts = []

    while len(huts) < 5:
        random_choice = random.choice(occupants)
        huts.append(random_choice)



def process_user_choice(): 
     message = "\033[1m"+ "Choose the hut to enter (1-5) " + "\033[0m"
     uc = input("\n" + message)
     index = int(uc)
     print("Revealing the occupants...")
     message = ""



def reveal_occcupants(index,huts,dotted_line):
    for i in range (len(huts)):
        occupant_info = "<%d:%s>"%(i+1,huts[i])
        if i + 1 == index:

            occipant_info = "\033[1m"+ "" + "\033[0m"
        message += occupant_info + " "
    print("\t" + message)
    print(dotted_line)



def enter_huts(index,huts,dotted_line): 
    print("\033[1m"+ "Entering Hut %d ..." %index + "\033[0m")

    if huts[index - 1] == 'clones':
        print("\033[1m"+ "There's Stormtrooper Here!!" + "\033[0m")
    else:
        print("\033[1m"+ "It's Safe here!" + "\033[0m")
    print(dotted_line)



def run():
    keep_playing = 'y'
    global occupants
    occupants = ['clones','friend','Jedi Hideout']
    width = 70
    dotted_line = '-' * width

    show_message(dotted_line, width)
    show_mission(dotted_line)

    while keep_playing == 'y':
         huts = occupy_huts()
         index = process_user_choice()
         reveal_occcupants(index,huts,dotted_line)
         enter_huts(index,huts,dotted_line)
         keep_playing = raw_input("Play Again?(y/n)")

if __name__ == '__main__':
    run()

而错误就在 def显示所有乘客。 TypeError:类型为“NoneType”的对象没有len

---

如何克服此错误，并请建议一种替代方法。len方法接受对象作为参数。 在您的例子中，在第43行，huts可能没有，因此您可能会得到一个错误

您应该在第42行之后插入如下条件

if huts is None:
    return

---

我的猜测是，小屋不是一种类型，因为“占领小屋”从未被命名。或者huts变量的作用域有问题-可以通过在occude_huts函数外将其声明为空集来解决

---

此外，您还可以利用Python的语法，将第43行更改为for hut in huts:。如果您还需要小屋的索引，请尝试枚举小屋中的小屋、i-hut:。

您的方法显示居住者作为小屋接收空值。也就是说，那种类型的小屋是没有的。这就是为什么无法获取此值的len。

此处：

while keep_playing == 'y':
     huts = occupy_huts()

您的Occuple_huts函数不返回任何内容—它填充了一个全局变量huts，但不返回它，因此如果您不显式返回某些内容，after the huts=occulation_huts语句huts现在是None—默认函数返回值。然后传递此now None huts变量以显示居住者：

解决方案很简单：修改Occups_huts，这样它就不会处理一个全局变量（这几乎总是一个非常糟糕的主意，并且不返回任何值），而是处理一个局部变量并返回它：

def occupy_huts():
    huts = []
    while len(huts) < 5:
        random_choice = random.choice(occupants)
        huts.append(random_choice)
    return huts

然后在运行中：

有趣的是，你传递的参数通常是常量，对程序的逻辑没有影响，比如虚线，但是在重要的事情上使用全局变量——实际上应该是另一种方式，在模块开始时将虚线声明为伪常量，而不必麻烦将其传递给函数

另外，请注意，您在这里的“过程\用户\选择”也有类似的问题：

---

因为您的process\u user\u choice函数也不会返回任何内容。您应该对其进行修改，使其返回其局部变量索引。

请将文本信息代码、错误作为文本而不是屏幕截图发布。调用Occuple_huts时，请检查run函数。这将掩盖症状，但无法解决真正的问题。

def occupy_huts():
    huts = []
    while len(huts) < 5:
        random_choice = random.choice(occupants)
        huts.append(random_choice)
    return huts

def occupy_huts(occupants):
    huts = []
    while len(huts) < 5:
        random_choice = random.choice(occupants)
        huts.append(random_choice)
    return huts

def run():
    keep_playing = 'y'
    occupants = ['clones','friend','Jedi Hideout']
    # ...
    while keep_playing == 'y':
         huts = occupy_huts(occupants)

while keep_playing == 'y':
     huts = occupy_huts()
     index = process_user_choice()