在Python中，用空格分隔字符串——保留带引号的子字符串

我有一个这样的字符串:

this is "a test"

我试图在Python中写一些东西，通过空格分割它，同时忽略引号中的空格。我想要的结果是:

['this', 'is', 'a test']

PS，我知道你会问“如果引号中有引号会发生什么，在我的应用程序中，这永远不会发生。

当前回答

我建议:

测试字符串:

s = 'abc "ad" \'fg\' "kk\'rdt\'" zzz"34"zzz "" \'\''

也要捕捉""和":

import re
re.findall(r'"[^"]*"|\'[^\']*\'|[^"\'\s]+',s)

结果:

['abc', '"ad"', "'fg'", '"kk\'rdt\'"', 'zzz', '"34"', 'zzz', '""', "''"]

忽略空的""和":

import re
re.findall(r'"[^"]+"|\'[^\']+\'|[^"\'\s]+',s)

结果:

['abc', '"ad"', "'fg'", '"kk\'rdt\'"', 'zzz', '"34"', 'zzz']

2015-09-09 13:19:59

其他回答

试试这个:

  def adamsplit(s):
    result = []
    inquotes = False
    for substring in s.split('"'):
      if not inquotes:
        result.extend(substring.split())
      else:
        result.append(substring)
      inquotes = not inquotes
    return result

一些测试字符串:

'This is "a test"' -> ['This', 'is', 'a test']
'"This is \'a test\'"' -> ["This is 'a test'"]

2008-09-17 04:31:38

你需要从内置的shlex模块中分离。

>>> import shlex
>>> shlex.split('this is "a test"')
['this', 'is', 'a test']

这应该是你想要的效果。

如果你想保留引号，那么你可以传递posix=False kwarg。

>>> shlex.split('this is "a test"', posix=False)
['this', 'is', '"a test"']

2008-09-17 04:27:32

如果你不关心子字符串

>>> 'a short sized string with spaces '.split()

性能:

>>> s = " ('a short sized string with spaces '*100).split() "
>>> t = timeit.Timer(stmt=s)
>>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
171.39 usec/pass

或者字符串模块

>>> from string import split as stringsplit; 
>>> stringsplit('a short sized string with spaces '*100)

性能:String模块的性能似乎比字符串方法更好

>>> s = "stringsplit('a short sized string with spaces '*100)"
>>> t = timeit.Timer(s, "from string import split as stringsplit")
>>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
154.88 usec/pass

或者你可以使用RE引擎

>>> from re import split as resplit
>>> regex = '\s+'
>>> medstring = 'a short sized string with spaces '*100
>>> resplit(regex, medstring)

性能

>>> s = "resplit(regex, medstring)"
>>> t = timeit.Timer(s, "from re import split as resplit; regex='\s+'; medstring='a short sized string with spaces '*100")
>>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
540.21 usec/pass

对于非常长的字符串，您不应该将整个字符串加载到内存中，而是将行分开或使用迭代循环

2008-09-17 05:46:57

由于这个问题带有正则表达式，我决定尝试正则表达式方法。我首先将引号部分中的所有空格替换为\x00，然后按空格分割，然后将\x00替换回每个部分中的空格。

这两个版本都做同样的事情，但是splitter比splitter2更具可读性。

import re

s = 'this is "a test" some text "another test"'

def splitter(s):
    def replacer(m):
        return m.group(0).replace(" ", "\x00")
    parts = re.sub('".+?"', replacer, s).split()
    parts = [p.replace("\x00", " ") for p in parts]
    return parts

def splitter2(s):
    return [p.replace("\x00", " ") for p in re.sub('".+?"', lambda m: m.group(0).replace(" ", "\x00"), s).split()]

print splitter2(s)

2008-09-17 06:08:38