如何从 python 中的文件中删除 space 以外的特殊字符？

Question

我有一个庞大的文本语料库（逐行），我想删除特殊字符但保持字符串的 space 和结构。

hello? there A-Z-R_T(,**), world, welcome to python.
this **should? the next line#followed- by@ an#other %million^ %%like $this.

应该是

hello there A Z R T world welcome to python
this should be the next line followed by another million like this

Answer 1

您也可以使用此模式 regex:

import re
a = '''hello? there A-Z-R_T(,**), world, welcome to python.
this **should? the next line#followed- by@ an#other %million^ %%like $this.'''

for k in a.split("\n"):
    print(re.sub(r"[^a-zA-Z0-9]+", ' ', k))
    # Or:
    # final = " ".join(re.findall(r"[a-zA-Z0-9]+", k))
    # print(final)

输出：

hello there A Z R T world welcome to python 
this should the next line followed by an other million like this

编辑：

否则，您可以将最后几行存储到 list:

final = [re.sub(r"[^a-zA-Z0-9]+", ' ', k) for k in a.split("\n")]
print(final)

输出：

['hello there A Z R T world welcome to python ', 'this should the next line followed by an other million like this ']

Answer 2

我认为 nfn neil 的回答很棒...但我只想添加一个简单的正则表达式来删除所有无单词字符，但是它会将下划线视为单词的一部分

print  re.sub(r'\W+', ' ', string)
>>> hello there A Z R_T world welcome to python

Answer 3

创建字典将特殊字符映射到 None

d = {c:None for c in special_characters}

对全文做一个translation table using the dictionary. Read the entire text into a variable and use str.translate。

Answer 4

一个更优雅的解决方案是

print(re.sub(r"\W+|_", " ", string))

>>> hello there A Z R T world welcome to python this should the next line followed by another million like this

在这里， re 是 python

中的 regex 模块

re.sub 将用 space 替换模式，即 " "

r'' 会将输入字符串视为原始字符串 (with \n)

\W 用于所有非单词，即所有特殊字符 *&^%$ 等，不包括下划线 _

+ 将匹配零到无限匹配，类似于 *（一到多）

| 是逻辑或

_代表下划线

Answer 5

你可以试试这个

import re
sentance = '''hello? there A-Z-R_T(,**), world, welcome to python. this **should? the next line#followed- by@ an#other %million^ %%like $this.'''
res = re.sub('[!,*)@#%(&$_?.^]', '', sentance)
print(res)

re.sub('["]') -> 在这里您可以添加要删除的符号

如何从 python 中的文件中删除 space 以外的特殊字符？

How to remove special characters except space from a file in python?

python

regex

string

file

string-formatting