RegEx - 如何删除空间

Question

s = "LEV606 (P), LEV230 (P)"
#Expected result: ['LEV606', 'LEV230']

# First attempt
In [3]: re.findall(r"[A-Z]{3}[0-9]{3}[ \(P\)]?", s)
Out[3]: ['LEV606 ', 'LEV230 ']

# Second attempt. The 'P' is not mandatory, can be other letter.
# Why this doesn't work?
In [4]: re.findall(r"[A-Z]{3}[0-9]{3}[ \([A-Z]{1}\)]?", s)
Out[4]: []

# Third attempt
# White space is still there. Why? I want to remove it from the answer
In [5]: re.findall(r"[A-Z]{3}[0-9]{3}[\s\(\w\)]?", s)
Out[5]: ['LEV606 ', 'LEV230 ']

Answer 1

您正在使用[...]语法错误;这是一个字符类，一个可以匹配的 set 字符。该类中列出的任何一个字符都匹配，因此可以是空格，(字符，P或);那个空间会做得很好。

使用非捕获组而不是字符类使额外文本可选，并使用您想要的部分的捕获组：

re.findall(r"([A-Z]{3}[0-9]{3})(?: \(P\))?", s)

演示：

>>> import re
>>> s = "LEV606 (P), LEV230 (P)"
>>> re.findall(r"([A-Z]{3}[0-9]{3})(?: \(P\))?", s)
['LEV606', 'LEV230']