似乎应该有一种比以下更简单的方法:
import string
s = "string. With. Punctuation?" # Sample string
out = s.translate(string.maketrans("",""), string.punctuation)
有?
似乎应该有一种比以下更简单的方法:
import string
s = "string. With. Punctuation?" # Sample string
out = s.translate(string.maketrans("",""), string.punctuation)
有?
当前回答
>>> s = "string. With. Punctuation?"
>>> s = re.sub(r'[^\w\s]','',s)
>>> re.split(r'\s*', s)
['string', 'With', 'Punctuation']
其他回答
在不太严格的情况下,单行线可能会有所帮助:
''.join([c for c in s if c.isalnum() or c.isspace()])
这个问题没有太多细节,所以我采取的方法是用最简单的解释来解决这个问题:去掉标点符号。
请注意,所提供的解决方案不考虑收缩词(例如,you are)或连字符词(例如肛门保留)。。。这是关于它们是否应该被视为标点符号的争论。。。也不能解释非英语字符集或类似的东西。。。因为问题中没有提到这些细节。有人认为空格是标点符号,这在技术上是正确的。。。但对我来说,这在当前问题的背景下毫无意义。
# using lambda
''.join(filter(lambda c: c not in string.punctuation, s))
# using list comprehension
''.join('' if c in string.punctuation else c for c in s)
使用Python从文本文件中删除停止词
print('====THIS IS HOW TO REMOVE STOP WORS====')
with open('one.txt','r')as myFile:
str1=myFile.read()
stop_words ="not", "is", "it", "By","between","This","By","A","when","And","up","Then","was","by","It","If","can","an","he","This","or","And","a","i","it","am","at","on","in","of","to","is","so","too","my","the","and","but","are","very","here","even","from","them","then","than","this","that","though","be","But","these"
myList=[]
myList.extend(str1.split(" "))
for i in myList:
if i not in stop_words:
print ("____________")
print(i,end='\n')
作为更新,我重写了Python 3中的@Brian示例,并对其进行了更改,以将正则表达式编译步骤移到函数内部。我在这里的想法是对使功能工作所需的每一步进行计时。也许您使用的是分布式计算,无法在工作人员之间共享regex对象,需要在每个工作人员处执行re.compile步骤。此外,我还很好奇地对Python 3的maketrans的两种不同实现进行计时
table = str.maketrans({key: None for key in string.punctuation})
vs
table = str.maketrans('', '', string.punctuation)
另外,我添加了另一种使用集合的方法,在这里我利用交集函数来减少迭代次数。
这是完整的代码:
import re, string, timeit
s = "string. With. Punctuation"
def test_set(s):
exclude = set(string.punctuation)
return ''.join(ch for ch in s if ch not in exclude)
def test_set2(s):
_punctuation = set(string.punctuation)
for punct in set(s).intersection(_punctuation):
s = s.replace(punct, ' ')
return ' '.join(s.split())
def test_re(s): # From Vinko's solution, with fix.
regex = re.compile('[%s]' % re.escape(string.punctuation))
return regex.sub('', s)
def test_trans(s):
table = str.maketrans({key: None for key in string.punctuation})
return s.translate(table)
def test_trans2(s):
table = str.maketrans('', '', string.punctuation)
return(s.translate(table))
def test_repl(s): # From S.Lott's solution
for c in string.punctuation:
s=s.replace(c,"")
return s
print("sets :",timeit.Timer('f(s)', 'from __main__ import s,test_set as f').timeit(1000000))
print("sets2 :",timeit.Timer('f(s)', 'from __main__ import s,test_set2 as f').timeit(1000000))
print("regex :",timeit.Timer('f(s)', 'from __main__ import s,test_re as f').timeit(1000000))
print("translate :",timeit.Timer('f(s)', 'from __main__ import s,test_trans as f').timeit(1000000))
print("translate2 :",timeit.Timer('f(s)', 'from __main__ import s,test_trans2 as f').timeit(1000000))
print("replace :",timeit.Timer('f(s)', 'from __main__ import s,test_repl as f').timeit(1000000))
这是我的结果:
sets : 3.1830138750374317
sets2 : 2.189873124472797
regex : 7.142953420989215
translate : 4.243278483860195
translate2 : 2.427158243022859
replace : 4.579746678471565
对于严肃的自然语言处理(NLP),您应该让像SpaCy这样的库通过标记化处理标点符号,然后您可以根据需要手动调整。
例如,您希望如何处理单词中的连字符?例外情况,如缩写?开始和结束引号?URL?在NLP中,将“let’s”这样的收缩分隔为“let”和“s”以进行进一步处理通常很有用。