我有一个像这样的字符串：
this is "a test"
我正在尝试用Python编写一些东西，用空格分隔它，同时忽略引号内的空格。我正在寻找的结果是：
['this','is','a test']
PS。我知道你会问“如果报价中有引号会发生什么，那么，在我的申请中，这将永远不会发生。
答案 0 :(得分：349)
您希望从shlex模块中拆分。
>>> import shlex
>>> shlex.split('this is "a test"')
['this', 'is', 'a test']
这应该完全符合您的要求。
答案 1 :(得分：54)
查看shlex模块，尤其是shlex.split。
>>> import shlex
>>> shlex.split('This is "a test"')
['This', 'is', 'a test']
答案 2 :(得分：33)
我看到这里的正则表达式看起来很复杂和/或错误。这让我感到惊讶，因为正则表达式语法可以很容易地描述“空白或者被引用的东西包围”，并且大多数正则表达式引擎（包括Python）可以在正则表达式上分割。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()]
说明：
[\\\"'] = double-quote or single-quote
.* = anything
( |X) = space or X
.strip() = remove space and empty-string separators
shlex可能会提供更多功能。
答案 3 :(得分：25)
根据您的使用情况，您可能还想查看csv模块：
import csv
lines = ['this is "a string"', 'and more "stuff"']
for row in csv.reader(lines, delimiter=" "):
print row
输出：
['this', 'is', 'a string']
['and', 'more', 'stuff']
答案 4 :(得分：12)
我使用shlex.split来处理70,000,000行鱿鱼日志，它太慢了。所以我改用了。
如果你有shlex的性能问题，请试试这个。
import re
def line_split(line):
return re.findall(r'[^"\s]\S*|".+?"', line)
答案 5 :(得分：8)
由于此问题标有正则表达式，我决定尝试使用正则表达式方法。我首先用\ x00替换引号部分中的所有空格，然后用空格分割，然后将\ x00替换回每个部分中的空格。
两个版本都做同样的事情，但拆分器比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)
答案 6 :(得分：4)
由于性能原因，self.assertTrue('ArgumentsException' in str(e.stderr))似乎更快。这是我使用最少贪心运算符保留外引号的解决方案：
re结果：
re.findall("(?:\".*?\"|\S)+", s)
它将诸如['this', 'is', '"a test"']
之类的结构放在一起，因为这些标记之间没有空格。如果字符串包含转义字符，则可以这样进行匹配：
aaa"bla blub"bbb请注意，它也通过模式的>>> a = "She said \"He said, \\\"My name is Mark.\\\"\""
>>> a
'She said "He said, \\"My name is Mark.\\""'
>>> for i in re.findall("(?:\".*?[^\\\\]\"|\S)+", a): print(i)
...
She
said
"He said, \"My name is Mark.\""
部分与空字符串""匹配。
答案 7 :(得分：3)
要保留引号，请使用此功能：
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
答案 8 :(得分：2)
为了解决一些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'))]
答案 9 :(得分：2)
不同答案的速度测试：
import re
import shlex
import csv
line = 'this is "a test"'
%timeit [p for p in re.split("( |\\\".*?\\\"|'.*?')", line) if p.strip()]
100000 loops, best of 3: 5.17 µs per loop
%timeit re.findall(r'[^"\s]\S*|".+?"', line)
100000 loops, best of 3: 2.88 µs per loop
%timeit list(csv.reader([line], delimiter=" "))
The slowest run took 9.62 times longer than the fastest. This could mean that an intermediate result is being cached.
100000 loops, best of 3: 2.4 µs per loop
%timeit shlex.split(line)
10000 loops, best of 3: 50.2 µs per loop
答案 10 :(得分：2)
已接受的shlex方法的主要问题在于，它不会忽略引用的子字符串之外的转义字符，并且在某些特殊情况下会产生一些意想不到的结果。
我有以下用例，其中我需要一个分割函数，该函数对输入字符串进行分割，以便保留单引号或双引号的子字符串，并能够在这样的子字符串中转义引号。无引号的字符串中的引号不应与其他任何字符区别对待。带有预期输出的一些示例测试用例：
input string | expected output =============================================== 'abc def' | ['abc', 'def'] "abc \\s def" | ['abc', '\\s', 'def'] '"abc def" ghi' | ['abc def', 'ghi'] "'abc def' ghi" | ['abc def', 'ghi'] '"abc \\" def" ghi' | ['abc " def', 'ghi'] "'abc \\' def' ghi" | ["abc ' def", 'ghi'] "'abc \\s def' ghi" | ['abc \\s def', 'ghi'] '"abc \\s def" ghi' | ['abc \\s def', 'ghi'] '"" test' | ['', 'test'] "'' test" | ['', 'test'] "abc'def" | ["abc'def"] "abc'def'" | ["abc'def'"] "abc'def' ghi" | ["abc'def'", 'ghi'] "abc'def'ghi" | ["abc'def'ghi"] 'abc"def' | ['abc"def'] 'abc"def"' | ['abc"def"'] 'abc"def" ghi' | ['abc"def"', 'ghi'] 'abc"def"ghi' | ['abc"def"ghi'] "r'AA' r'.*_xyz$'" | ["r'AA'", "r'.*_xyz$'"]
我最终得到了以下函数来拆分字符串，以便所有输入字符串的预期输出结果：
import re
def quoted_split(s):
def strip_quotes(s):
if s and (s[0] == '"' or s[0] == "'") and s[0] == s[-1]:
return s[1:-1]
return s
return [strip_quotes(p).replace('\\"', '"').replace("\\'", "'") \
for p in re.findall(r'"(?:\\.|[^"])*"|\'(?:\\.|[^\'])*\'|[^\s]+', s)]
以下测试应用程序将检查其他方法（目前为shlex和csv）和自定义拆分实现的结果：
#!/bin/python2.7
import csv
import re
import shlex
from timeit import timeit
def test_case(fn, s, expected):
try:
if fn(s) == expected:
print '[ OK ] %s -> %s' % (s, fn(s))
else:
print '[FAIL] %s -> %s' % (s, fn(s))
except Exception as e:
print '[FAIL] %s -> exception: %s' % (s, e)
def test_case_no_output(fn, s, expected):
try:
fn(s)
except:
pass
def test_split(fn, test_case_fn=test_case):
test_case_fn(fn, 'abc def', ['abc', 'def'])
test_case_fn(fn, "abc \\s def", ['abc', '\\s', 'def'])
test_case_fn(fn, '"abc def" ghi', ['abc def', 'ghi'])
test_case_fn(fn, "'abc def' ghi", ['abc def', 'ghi'])
test_case_fn(fn, '"abc \\" def" ghi', ['abc " def', 'ghi'])
test_case_fn(fn, "'abc \\' def' ghi", ["abc ' def", 'ghi'])
test_case_fn(fn, "'abc \\s def' ghi", ['abc \\s def', 'ghi'])
test_case_fn(fn, '"abc \\s def" ghi', ['abc \\s def', 'ghi'])
test_case_fn(fn, '"" test', ['', 'test'])
test_case_fn(fn, "'' test", ['', 'test'])
test_case_fn(fn, "abc'def", ["abc'def"])
test_case_fn(fn, "abc'def'", ["abc'def'"])
test_case_fn(fn, "abc'def' ghi", ["abc'def'", 'ghi'])
test_case_fn(fn, "abc'def'ghi", ["abc'def'ghi"])
test_case_fn(fn, 'abc"def', ['abc"def'])
test_case_fn(fn, 'abc"def"', ['abc"def"'])
test_case_fn(fn, 'abc"def" ghi', ['abc"def"', 'ghi'])
test_case_fn(fn, 'abc"def"ghi', ['abc"def"ghi'])
test_case_fn(fn, "r'AA' r'.*_xyz$'", ["r'AA'", "r'.*_xyz$'"])
def csv_split(s):
return list(csv.reader([s], delimiter=' '))[0]
def re_split(s):
def strip_quotes(s):
if s and (s[0] == '"' or s[0] == "'") and s[0] == s[-1]:
return s[1:-1]
return s
return [strip_quotes(p).replace('\\"', '"').replace("\\'", "'") for p in re.findall(r'"(?:\\.|[^"])*"|\'(?:\\.|[^\'])*\'|[^\s]+', s)]
if __name__ == '__main__':
print 'shlex\n'
test_split(shlex.split)
print
print 'csv\n'
test_split(csv_split)
print
print 're\n'
test_split(re_split)
print
iterations = 100
setup = 'from __main__ import test_split, test_case_no_output, csv_split, re_split\nimport shlex, re'
def benchmark(method, code):
print '%s: %.3fms per iteration' % (method, (1000 * timeit(code, setup=setup, number=iterations) / iterations))
benchmark('shlex', 'test_split(shlex.split, test_case_no_output)')
benchmark('csv', 'test_split(csv_split, test_case_no_output)')
benchmark('re', 'test_split(re_split, test_case_no_output)')
输出：
shlex [ OK ] abc def -> ['abc', 'def'] [FAIL] abc \s def -> ['abc', 's', 'def'] [ OK ] "abc def" ghi -> ['abc def', 'ghi'] [ OK ] 'abc def' ghi -> ['abc def', 'ghi'] [ OK ] "abc \" def" ghi -> ['abc " def', 'ghi'] [FAIL] 'abc \' def' ghi -> exception: No closing quotation [ OK ] 'abc \s def' ghi -> ['abc \\s def', 'ghi'] [ OK ] "abc \s def" ghi -> ['abc \\s def', 'ghi'] [ OK ] "" test -> ['', 'test'] [ OK ] '' test -> ['', 'test'] [FAIL] abc'def -> exception: No closing quotation [FAIL] abc'def' -> ['abcdef'] [FAIL] abc'def' ghi -> ['abcdef', 'ghi'] [FAIL] abc'def'ghi -> ['abcdefghi'] [FAIL] abc"def -> exception: No closing quotation [FAIL] abc"def" -> ['abcdef'] [FAIL] abc"def" ghi -> ['abcdef', 'ghi'] [FAIL] abc"def"ghi -> ['abcdefghi'] [FAIL] r'AA' r'.*_xyz$' -> ['rAA', 'r.*_xyz$'] csv [ OK ] abc def -> ['abc', 'def'] [ OK ] abc \s def -> ['abc', '\\s', 'def'] [ OK ] "abc def" ghi -> ['abc def', 'ghi'] [FAIL] 'abc def' ghi -> ["'abc", "def'", 'ghi'] [FAIL] "abc \" def" ghi -> ['abc \\', 'def"', 'ghi'] [FAIL] 'abc \' def' ghi -> ["'abc", "\\'", "def'", 'ghi'] [FAIL] 'abc \s def' ghi -> ["'abc", '\\s', "def'", 'ghi'] [ OK ] "abc \s def" ghi -> ['abc \\s def', 'ghi'] [ OK ] "" test -> ['', 'test'] [FAIL] '' test -> ["''", 'test'] [ OK ] abc'def -> ["abc'def"] [ OK ] abc'def' -> ["abc'def'"] [ OK ] abc'def' ghi -> ["abc'def'", 'ghi'] [ OK ] abc'def'ghi -> ["abc'def'ghi"] [ OK ] abc"def -> ['abc"def'] [ OK ] abc"def" -> ['abc"def"'] [ OK ] abc"def" ghi -> ['abc"def"', 'ghi'] [ OK ] abc"def"ghi -> ['abc"def"ghi'] [ OK ] r'AA' r'.*_xyz$' -> ["r'AA'", "r'.*_xyz$'"] re [ OK ] abc def -> ['abc', 'def'] [ OK ] abc \s def -> ['abc', '\\s', 'def'] [ OK ] "abc def" ghi -> ['abc def', 'ghi'] [ OK ] 'abc def' ghi -> ['abc def', 'ghi'] [ OK ] "abc \" def" ghi -> ['abc " def', 'ghi'] [ OK ] 'abc \' def' ghi -> ["abc ' def", 'ghi'] [ OK ] 'abc \s def' ghi -> ['abc \\s def', 'ghi'] [ OK ] "abc \s def" ghi -> ['abc \\s def', 'ghi'] [ OK ] "" test -> ['', 'test'] [ OK ] '' test -> ['', 'test'] [ OK ] abc'def -> ["abc'def"] [ OK ] abc'def' -> ["abc'def'"] [ OK ] abc'def' ghi -> ["abc'def'", 'ghi'] [ OK ] abc'def'ghi -> ["abc'def'ghi"] [ OK ] abc"def -> ['abc"def'] [ OK ] abc"def" -> ['abc"def"'] [ OK ] abc"def" ghi -> ['abc"def"', 'ghi'] [ OK ] abc"def"ghi -> ['abc"def"ghi'] [ OK ] r'AA' r'.*_xyz$' -> ["r'AA'", "r'.*_xyz$'"] shlex: 0.281ms per iteration csv: 0.030ms per iteration re: 0.049ms per iteration
因此，性能要比shlex好得多，并且可以通过预编译正则表达式来进一步提高性能，在这种情况下，它的性能将优于csv方法。
答案 11 :(得分：1)
嗯，似乎无法找到“回复”按钮...无论如何，这个答案是基于Kate的方法，但正确地将字符串拆分为包含转义引号的子字符串，并删除了引号的开头和结尾引号子：
[i.strip('"').strip("'") for i in re.split(r'(\s+|(?<!\\)".*?(?<!\\)"|(?<!\\)\'.*?(?<!\\)\')', string) if i.strip()]
这适用于像'This is " a \\\"test\\\"\\\'s substring"'这样的字符串（不幸的是，疯狂的标记是阻止Python删除转义的必要条件）。
如果不想在返回列表中的字符串中生成转义符，则可以使用该函数稍微更改的版本：
[i.strip('"').strip("'").decode('string_escape') for i in re.split(r'(\s+|(?<!\\)".*?(?<!\\)"|(?<!\\)\'.*?(?<!\\)\')', string) if i.strip()]
答案 12 :(得分：1)
上面讨论的shlex的unicode问题（最佳答案）似乎在2.7.2+中间接解决（间接） http://bugs.python.org/issue6988#msg146200
（单独回答，因为我无法发表评论）
答案 13 :(得分：1)
作为一种选择，尝试tssplit：
CustomScrollView(
slivers: <Widget>[
SliverAppBar(
title: Text('Test'),
),
SliverList(
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
return Container(
child: Container(
child: Column(
children: <Widget>[
Container(
child: Text(
'Index is $index'.toUpperCase(),
),
alignment: Alignment.centerLeft,
padding: EdgeInsets.only(bottom: 10.0),
),
Container(height: 200.0)
],
),
constraints: BoxConstraints.tightForFinite(width: 200),
decoration: BoxDecoration(
color:
index % 2 == 0 ? Color(0XFF45766E) : Color(0XFFECB141),
borderRadius: BorderRadius.only(
topLeft: Radius.circular(40.0),
topRight: Radius.circular(40.0),
),
),
padding: EdgeInsets.only(
left: 20.0,
top: 10.0,
),
),
decoration: BoxDecoration(
color: index % 2 == 0 ? Color(0XFFECB141) : Color(0XFF45766E),
),
);
},
),
),
],
);
答案 14 :(得分：-1)
如果你不关心子字符串而不是简单的
>>> '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
或字符串模块
>>> from string import split as stringsplit;
>>> stringsplit('a short sized string with spaces '*100)
性能：字符串模块似乎比字符串方法表现更好
>>> 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
或者您可以使用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
对于很长的字符串，你不应该将整个字符串加载到内存中，而是分割行或使用迭代循环
答案 15 :(得分：-2)
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'"]