Question

我在使用某些Python代码时遇到了一些麻烦。我有一个名为＆＃34; big.txt＆＃34;的大文本文件。我在我的代码中迭代它以将每个单词排序成一个数组（或列表），然后再次迭代它以删除任何不在字母表中的字符。我还有一个名为worddistance的函数，它会查看两个单词的相似程度，然后返回一个分数。我有另一个名为autocorrect的函数。我希望将这个函数传递给拼写错误的单词，然后打印一个'Did you mean...'句子，其中包含worddistance函数得分较低的单词（每当发现差异时，该函数会向计数器添加1 - 较低得分，越相似）。
奇怪的是，我不断收到错误：

"Index Error: string index out of range"

我对正在发生的事感到茫然！

我的代码如下。

提前感谢回复，
塞缪尔·诺顿

f = open("big.txt", "r")

words = list()

temp_words = list()
for line in f:
    for word in line.split():
        temp_words.append(word.lower())

allowed_characters = 'abcdefghijklmnopqrstuvwxyz'       
for item in temp_words:
    temp_new_word = ''
    for char in item:
        if char in allowed_characters:
            temp_new_word += char
        else:
            continue
    words.append(temp_new_word)
list(set(words)).sort()

def worddistance(word1, word2):
    counter = 0
    if len(word1) > len(word2):
        counter += len(word1) - len(word2)
        new_word1 = word1[:len(word2) + 1] 
        for char in range(0, len(word2) + 1) :
            if word2[char] != new_word1[char]:
                counter += 1
            else:
                continue
    elif len(word2) > len(word1):
        counter += len(word2) - len(word1)
        new_word2 = word2[:len(word1) + 1]
        for char in range(0, len(word1) + 1):
            if word1[char] != word2[char]:
                counter += 1
            else:
                continue
    return counter

def autocorrect(word):
    word.lower()
    if word in words:
        print("The spelling is correct.")
        return
    else:
        suggestions = list()
        for item in words:
            diff = worddistance(word, item)
            if diff == 1:
                suggestions.append(item)
       print("Did you mean: ", end = ' ')

    if len(suggestions) == 1:
                print(suggestions[0])
                return

    else:
        for i in range(0, len(suggestions)):
            if i == len(suggestons) - 1:
                print("or " + suggestions[i] + "?")
                return
            print(suggestions[i] + ", ", end="")
            return

Answer 1

在worddistance()中，for char in range(0, len(word1) + 1):看起来应该是：

for char in range(len(word1)):

for char in range(0, len(word2) + 1) :应该是：

for char in range(len(word2)):

顺便说一下，list(set(words)).sort()正在排序一个临时列表，这可能不是你想要的。它应该是：

words = sorted(set(words))

Answer 2

如其他评论中所述，您应该range(len(word1))。

除此之外： - 您应该考虑word1和单词长度相同的情况#len(word2) == len(word1) - 你还应该注意命名。在wordDistance函数的第二个条件

 if word1[char] != word2[char]:

您应该与new_word2

进行比较

if word1[char] != new_word2[char]:

- 在自动更正中，您应该将低级分配给word= word.lower()

words= [] 
for item in temp_words:
    temp_new_word = ''
    for char in item:
        if char in allowed_characters:
            temp_new_word += char
        else:
            continue
    words.append(temp_new_word)
words= sorted(set(words))

def worddistance(word1, word2):
    counter = 0
    if len(word1) > len(word2):
        counter += len(word1) - len(word2)
        new_word1 = word1[:len(word2) + 1] 
        for char in range(len(word2)) :
            if word2[char] != new_word1[char]:
                counter += 1
    elif len(word2) > len(word1):
        counter += len(word2) - len(word1)
        new_word2 = word2[:len(word1) + 1]
        for char in range(len(word1)):
            if word1[char] != new_word2[char]:  #This is a problem
                counter += 1
    else:  #len(word2) == len(word1)      #You missed this case
        for char in range(len(word1)):
            if word1[char] != word2[char]:  
                counter += 1
    return counter

def autocorrect(word):
    word= word.lower() #This is a problem
    if word in words:
        print("The spelling is correct.")
    else:
        suggestions = list()
        for item in words:
            diff = worddistance(word, item)
            print diff
            if diff == 1:
                suggestions.append(item)
        print("Did you mean: ")

        if len(suggestions) == 1:
            print(suggestions[0])

        else:
            for i in range(len(suggestions)):
                if i == len(suggestons) - 1:
                    print("or " + suggestions[i] + "?")
                print(suggestions[i] + ", ")

下次尝试使用像enumerate这样的Python内置函数，以避免使用i in range(list)，然后使用list[i]，len代替计数器......等等

例如：你的距离函数可以这样写，或者更简单。

def distance(word1, word2):
    counter= max(len(word1),len(word2))- min(len(word1),len(word2))
    if len(word1) > len(word2):
        counter+= len([x for x,z in zip (list(word2), list(word1[:len(word2) + 1])) if x!=z])
    elif len(word2) > len(word1):
        counter+= len([x for x,z in zip (list(word1), list(word2[:len(word1) + 1])) if x!=z])
    else:
        counter+= len([x for x,z in zip (list(word1), list(word2)) if x!=z])
    return counter

比较字符串时的索引错误 - Python

2 个答案: