你如何在三重嵌套列表中搜索？

Question

我正在尝试搜索 python 中的三重嵌套列表。我想出了一个超级混乱的方法，但行不通。你如何有效地做到这一点？我正在使用 python 3. 我尝试搜索的列表不一定在每个插槽中嵌套三重。

这是我写的糟糕而混乱的方式，由于某种原因不起作用。

HELLO = ["hello", "hi"]
GOODBYE = ["goodbye", "bye"]

POLITENESS = [HELLO, GOODBYE]

FRUITS = ["apples", "bananas"]
MEAT = ["pork", "chicken"]

FOODS = [FRUITS, MEAT]

random_Words = ["shoe", "bicycle", "school"]


#Here is the triple nested list.
VOCABULARY = [POLITENESS, FOODS, random_Words, "house"]

knowWord = False
userInput = input("say whatever")

#this checks for userInput in triple nested lists
#first it checks whether the first slot in vocabulary is nested,
#if that's the case it checks if the lists wiithin vocabulary[i] is nested and goes on like that.
#when finally it comes to a list that is not nested it checks for userInput in that list.

for i in range(len(VOCABULARY)):
    #if list item is not nested
    if any(isinstance(j, list) for j in VOCABULARY[i]) == False:
            #if userinput is inside a non-nested list
            if userInput not in VOCABULARY[i]:
                continue
            else:
                #if userInput is found
                knowWord = True
                break
    #if list is nested
    else:
        continue
    for k in range(len(VOCABULARY[i])):
        if any(isinstance(l, list) for l in VOCABULARY[i][k]) == False:
                if userInput not in VOCABULARY[i][k]:
                    continue
                else:
                    knowWord = True
                    break
        else:
            continue
        for m in range(len(VOCABULARY[i][k])):
            if any(isinstance(n, list) for n in VOCABULARY[i][k][m]) == False:
                    if userInput not in VOCABULARY[i][k][m]:
                        continue
                    else:
                        knowWord = True
                        break
            else:
                continue

if knowWord == True:
    print("YES")
else:
    print("I don't know that word")

Answer 1

要使您的代码正常工作，您只需删除这些行：

#if list is nested
else:
    continue

为了让代码更漂亮，你可以使用递归。这个函数会找出一个给定的词是否在里面，无论你有多少嵌套列表：

def findWord(word,l):
    words = []
    lists = []
    for entry in l:
        if isinstance(entry,list):
            lists.append(entry)
        else:
            words.append(entry)


    for w in words:
        if w == word:
            return True

    for ls in lists:
        if findWord(word,ls) == True:
            return True

    return False



if findWord(userInput,VOCABULARY) == True:
    print("YES")
else:
    print("I don't know that word")

Answer 2

如果您只想使用嵌套列表，那么下面可能会对您有所帮助，否则，也可以使用上面提到的将列表展平或转换为 Set 的解决方案

def check(val):
    for i in itertools.chain(VOCABULARY):
        if val in i:
            return True
    return False

你如何在三重嵌套列表中搜索？

How do you search in triple nested lists?

python

nested-lists