如何使这个代码忽略句子中的所有标点符号？

Question

我创建了这段代码来分析一个输入句子，以便用户在其中搜索某个单词。然而，我似乎不知道如何使它在输入句子中的所有标点符号被忽略。我之所以需要这样做是因为，如果输入“hello there，friend”这样的句子，“there”这个词就被算作“there”，因此如果用户正在搜索“there”，它会说它不在句子中。请帮帮我。我对python真的很陌生。你知道吗

print("Please enter a sentence")
sentence=input()
lowersen=(sentence.lower())
print(lowersen)
splitlowersen=(lowersen.split())
print (splitlowersen)
print("Enter word")
word=input()
lword=(word.lower())
if lword in splitlowersen:
    print(lword, "is in sentence")
    for i, j in enumerate (splitlowersen):
        if j==lword:
            print(""+lword+"","is in position", i+1)    

if lword not in splitlowersen:
    print (lword, "is not in sentence")

Answer 1

print("Please enter a sentence")
sentence=input()
lowersen=(sentence.lower())
print(lowersen)
splitlowersen=(lowersen.strip())
#to remove punctuations
splitlowersen = "".join(c for c in splitlowersen if c not in ('!','.',':'))
print("Enter word")
word=input()
lword=(word.lower())
if lword in splitlowersen:
    print(lword, "is in sentence")
    for i, j in enumerate (splitlowersen):
        if j==lword:
            print(""+lword+"","is in position", i+1)

if lword not in splitlowersen:
    print (lword, "is not in sentence")

输出：

Please enter a sentence
hello, friend
hello, friend
Enter word
hello
hello is in sentence

Answer 2

这可能有点冗长，但在Python3。你知道吗

# This will remove all non letter characters and spaces from the sentence
sentence = ''.join(filter(lambda x: x.isalpha() or x == ' ', sentence)
# the rest of your code will work after this.

这里有一些先进的概念。你知道吗

Filter将接受一个函数和一个iterible，该函数和iterible返回一个生成器，其中的项不会从函数返回true https://docs.python.org/3/library/functions.html#filter

Lambda将创建一个匿名函数，为我们检查每个字母。 https://docs.python.org/3/reference/expressions.html#lambda

isalpha（）将检查所讨论的字母是否是一个字母。 后跟x==''，可以看到它可能是一个空格。 https://docs.python.org/3.6/library/stdtypes.html?highlight=isalpha#str.isalpha

''。join将获取筛选器的结果并将其放回字符串中。 https://docs.python.org/3.6/library/stdtypes.html?highlight=isalpha#str.join

Answer 3

您可以拆分所有标点符号上的字符串：

s = "This, is a line."
f = s.split(".,!?")
>>>> f = ["This", "is", "a", "line"]