作为一个选项，尝试tssplit:

In [1]: from tssplit import tssplit
In [2]: tssplit('this is "a test"', quote='"', delimiter='')
Out[2]: ['this', 'is', 'a test']

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

我看到这里的正则表达式方法看起来很复杂和/或错误。这让我很惊讶，因为正则表达式语法可以很容易地描述“空格或引号包围的东西”，而且大多数正则表达式引擎(包括Python的)都可以在正则表达式上进行拆分。所以如果你要使用正则表达式，为什么不直接说出你的意思呢?：

test = 'this is "a test"'  # or "this is 'a test'"
# pieces = [p for p in re.split("( |[\\\"'].*[\\\"'])", test) if p.strip()]
# From comments, use this:
pieces = [p for p in re.split("( |\\\".*?\\\"|'.*?')", test) if p.strip()]

解释:

[\\\"'] = double-quote or single-quote
.* = anything
( |X) = space or X
.strip() = remove space and empty-string separators

不过，Shlex可能提供更多的特性。

要保留引号，使用这个函数:

def getArgs(s):
    args = []
    cur = ''
    inQuotes = 0
    for char in s.strip():
        if char == ' ' and not inQuotes:
            args.append(cur)
            cur = ''
        elif char == '"' and not inQuotes:
            inQuotes = 1
            cur += char
        elif char == '"' and inQuotes:
            inQuotes = 0
            cur += char
        else:
            cur += char
    args.append(cur)
    return args

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)

要解决某些Python 2版本中的unicode问题，我建议:

from shlex import split as _split
split = lambda a: [b.decode('utf-8') for b in _split(a.encode('utf-8'))]