Question

我是初学者，最近开始进行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()

并且错误在体内 def reveal_occupants 。＆＃34; TypeError：类型对象＆＃39; NoneType＆＃39;没有len（） ＆＃34;

如何克服这个错误，请建议另一种方法

Answer 1

这里：

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

您的occupy_huts()函数没有返回任何内容（它填充全局变量huts但不返回它），因此huts = occupy_huts()语句{{ 1}}现在是huts（默认函数返回值，如果你没有明确地返回一些东西）。然后，您将此（None）None变量传递给huts：

reveal_occupants()

解决方案很简单：修改reveal_occcupants(index,huts,dotted_line)所以不是在处理全局（这几乎总是一个非常糟糕的主意）并返回occupy_huts，而是在局部变量上工作并返回它： / p>

None

虽然我们正在使用它，但您def occupy_huts(): huts = [] while len(huts) < 5: random_choice = random.choice(occupants) huts.append(random_choice) return huts也使用global，这很脆弱（如果在创建此变量之前调用occupants将会中断），虽然你可以把它作为参数传递：

occupy_huts()

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

run()

这里有趣的是你传递的参数主要是常量并且对程序的逻辑没有影响（即def run(): keep_playing = 'y' occupants = ['clones','friend','Jedi Hideout'] # ... while keep_playing == 'y': huts = occupy_huts(occupants)），但是对于重要的事情使用全局变量 - 应该真的反之亦然（在模块开头将dotted_lines声明为伪常量并且不要将其传递给函数）;）

另请注意，此处dotted_lines存在类似问题：

process_user_choice()

因为您的while keep_playing == 'y': huts = occupy_huts() index = process_user_choice()函数也没有返回任何内容。您应该修改它，以便返回其本地变量process_user_choice()。

Answer 2

len（）方法接受一个对象作为参数。在你的情况下，在第43行，小屋可能是无，所以你可能会收到错误。

你应该在第42行之后插入如下条件

if huts is None:
    return

Answer 3

我的猜测是“huts”是None-type，因为从未调用了occupy_huts（）。或者“huts”变量的范围存在问题 - 可以通过将其声明为occupy_huts（）函数之外的空集来清除它。

此外，您可以利用Python的语法并将第43行更改为“for hut in huts：”。如果您还需要小屋的索引，请尝试“for hut，i-hut in enumerate（huts）：”。

Answer 4

你的方法＆＃34; reveal_occupants＆＃34;作为小屋获得空值。这意味着，那种类型的小屋是无。这就是为什么你无法获得这个价值的原因。

Python开发[类型错误]

4 个答案: