python返回列表中的重复项

Question

如何从字符串列表中找到重复列表？ 给出了清理函数

def clean_up(s):
""" (str) -> str

Return a new string based on s in which all letters have been
converted to lowercase and punctuation characters have been stripped 
from both ends. Inner punctuation is left untouched. 

>>> clean_up('Happy Birthday!!!')
'happy birthday'
>>> clean_up("-> It's on your left-hand side.")
" it's on your left-hand side"
"""

punctuation = """!"',;:.-?)([]<>*#\n\t\r"""
result = s.lower().strip(punctuation)
return result

这是我的复制函数。

def duplicate(text):
""" (list of str) -> list of str

>>> text = ['James Fennimore Cooper\n', 'Peter, Paul, and Mary\n',
'James Gosling\n']
>>> duplicate(text)
['james']
"""

cleaned = ''
non_duplicate = []
unique = []
for word in text:
    cleaned += clean_up(word).replace(",", " ") + " "
    words = cleaned.split()        
    for word in words:
         if word in unique:

我被困在这里.. 我不能使用字典或任何其他技术来计算文本中每个单词的频率。 请帮忙..

Answer 1

你这里有问题：

cleaned += clean_up(word).replace(",", " ") + " "

这一行将新的“单词”添加到到目前为止所有单词的增长字符串中。因此，每次通过for 循环时，您都会重新检查到目前为止您看到的所有单词。

相反，您需要这样做：

for phrase in text:
    for word in phrase.split(" "):
        word = clean_up(word)

这意味着您只处理每个单词一次。然后，您可能需要将其添加到您的一个列表中，具体取决于它是否已经在其中一个列表中。我建议您将您的列表称为seen 和duplicates，以便更清楚地了解发生了什么。