Python中非消费的正则表达式分割

Question

如何在一个字符串中根据某个分隔符进行拆分，同时把这个分隔符保留在前面的字符串里呢？

>>> text = "This is an example. Is it made up of more than once sentence? Yes, it is."
>>> re.split("[\.\?!] ", text)
['This is an example', 'Is it made up of more than one sentence', 'Yes, it is.']

我希望得到的结果是这样的。

['This is an example.', 'Is it made up of more than one sentence?', 'Yes, it is.']

到目前为止，我只尝试过一种前瞻断言，但这样做根本没有拆分成功。

Answer 1

>>> re.split("(?<=[\.\?!]) ", text)
['This is an example.', 'Is it made up of more than once sentence?', 'Yes, it is.']

关键在于使用一种叫做回顾断言的东西，写法是?<=。

Answer 2

import re

text = "This is an example.A particular case.Made up of more "\
       "than once sentence?Yes, it is.But no blank !!!That's"\
       " a problem ????Yes.I think so! :)"


for x in re.split("(?<=[\.\?!]) ", text):
    print repr(x)

print '\n'

for x in re.findall("[^.?!]*[.?!]|[^.?!]+(?=\Z)",text):
    print repr(x)

结果

"This is an example.A particular case.Made up of more than once sentence?Yes, it is.But no blank !!!That'sa problem ????Yes.I think so!"
':)'


'This is an example.'
'A particular case.'
'Made up of more than once sentence?'
'Yes, it is.'
'But no blank !'
'!'
'!'
"That's a problem ?"
'?'
'?'
'?'
'Yes.'
'I think so!'
' :)'

.

编辑

还有

import re

text = "! This is an example.A particular case.Made up of more "\
       "than once sentence?Yes, it is.But no blank !!!That's"\
       " a problem ????Yes.I think so! :)"

res = re.split('([.?!])',text)

print [ ''.join(res[i:i+2]) for i in xrange(0,len(res),2) ]

给出

['!', ' This is an example.', 'A particular case.', 'Made up of more than once sentence?', 'Yes, it is.', 'But no blank !', '!', '!', "That's a problem ?", '?', '?', '?', 'Yes.', 'I think so!', ' :)']