如何使用正则表达式获取嵌套组

Question

我需要你帮助我遵循正则表达式。我有一条短信

"[Hello|Hi]. We are [inviting | calling] you at position [[junior| mid junior]|senior] developer."

使用正则表达式我想得到

[Hello|Hi]
[inviting | calling]
[[junior| mid junior]|senior]

以下 rexeg (\[[^\[$\]\]]*\])

给我 [Hello|Hi] [inviting | calling] [junior| mid junior]

那么我应该如何修复它以获得正确的输出？

Answer 1

让我们定义您的字符串并导入 re:

>>> s = "[Hello|Hi]. We are [inviting | calling] you at position [[junior| mid junior]|senior] developer."
>>> import re

现在，尝试：

>>> re.findall(r'\[ (?:[^][]* \[ [^][]* \])* [^][]*  \]', s, re.X)
['[Hello|Hi]', '[inviting | calling]', '[[junior| mid junior]|senior]']

更详细

考虑这个脚本：

$ cat script.py
import re
s = "[Hello|Hi]. We are [inviting | calling] you at position [[junior| mid junior]|senior] developer."

matches = re.findall(r'''\[       # Opening bracket
        (?:[^][]* \[ [^][]* \])*  # Zero or more non-bracket characters followed by a [, followed by zero or more non-bracket characters, followed by a ]
        [^][]*                    # Zero or more non-bracket characters
        \]                        # Closing bracket
        ''',
        s,
        re.X)
print('\n'.join(matches))

这会产生输出：

$ python script.py
[Hello|Hi]
[inviting | calling]
[[junior| mid junior]|senior]

Answer 2

您可以将以下代码与 PyPi regex module 和类似 PCRE 的 r'\[(?:[^][]++|(?R))*]' 正则表达式一起使用：

>>> import regex
>>> s = "[Hello|Hi]. We are [inviting | calling] you at position [[junior| mid junior]|senior] developer."
>>> r = regex.compile(r'\[(?:[^][]++|(?R))*]')
>>> print(r.findall(s))
['[Hello|Hi]', '[inviting | calling]', '[[junior| mid junior]|senior]']
>>>

参见regex demo。

\[(?:[^][]++|(?R))*] 匹配 [，然后是 ] 和 [ 以外的零个或多个 1+ 字符序列或整个括号表达式 [...]，然后是结束符 ].

Answer 3

您可以使用简单的 stack 代替 recursive regex

x="[Hello|Hi]. We are [inviting | calling] you at position [[junior| mid junior]|senior] developer.[sd[sd[sd][sd]]]"
l=[]
st=[]
start=None
for i,j in enumerate(x):
    if j=='[':
        if j not in st:
            start = i
        st.append(j)
    elif j==']':
        st.pop()
        if not st:
            l.append(x[start:i+1])
print l

输出：['[Hello|Hi]', '[inviting | calling]', '[[junior| mid junior]|senior]', '[sd[sd[sd][sd]]]']

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