这是最简单的解释。这是我正在使用的:
re.split('\W', 'foo/bar spam\neggs')
>>> ['foo', 'bar', 'spam', 'eggs']
这是我想要的:
someMethod('\W', 'foo/bar spam\neggs')
>>> ['foo', '/', 'bar', ' ', 'spam', '\n', 'eggs']
原因是我想把一个字符串分割成令牌,操作它,然后再把它组合在一起。
这是最简单的解释。这是我正在使用的:
re.split('\W', 'foo/bar spam\neggs')
>>> ['foo', 'bar', 'spam', 'eggs']
这是我想要的:
someMethod('\W', 'foo/bar spam\neggs')
>>> ['foo', '/', 'bar', ' ', 'spam', '\n', 'eggs']
原因是我想把一个字符串分割成令牌,操作它,然后再把它组合在一起。
当前回答
如果你只有一个分隔符,你可以使用列表推导式:
text = 'foo,bar,baz,qux'
sep = ','
附加/将分隔符:
result = [x+sep for x in text.split(sep)]
#['foo,', 'bar,', 'baz,', 'qux,']
# to get rid of trailing
result[-1] = result[-1].strip(sep)
#['foo,', 'bar,', 'baz,', 'qux']
result = [sep+x for x in text.split(sep)]
#[',foo', ',bar', ',baz', ',qux']
# to get rid of trailing
result[0] = result[0].strip(sep)
#['foo', ',bar', ',baz', ',qux']
分隔符作为它自己的元素:
result = [u for x in text.split(sep) for u in (x, sep)]
#['foo', ',', 'bar', ',', 'baz', ',', 'qux', ',']
results = result[:-1] # to get rid of trailing
其他回答
在下面的代码中,对这个问题有一个简单、高效且经过测试的答案。代码中有解释其中所有内容的注释。
我保证它并不像看起来那么可怕——它实际上只有13行代码!其余的都是注释、文档和断言
def split_including_delimiters(input: str, delimiter: str):
"""
Splits an input string, while including the delimiters in the output
Unlike str.split, we can use an empty string as a delimiter
Unlike str.split, the output will not have any extra empty strings
Conequently, len(''.split(delimiter))== 0 for all delimiters,
whereas len(input.split(delimiter))>0 for all inputs and delimiters
INPUTS:
input: Can be any string
delimiter: Can be any string
EXAMPLES:
>>> split_and_keep_delimiter('Hello World ! ',' ')
ans = ['Hello ', 'World ', ' ', '! ', ' ']
>>> split_and_keep_delimiter("Hello**World**!***", "**")
ans = ['Hello', '**', 'World', '**', '!', '**', '*']
EXAMPLES:
assert split_and_keep_delimiter('-xx-xx-','xx') == ['-', 'xx', '-', 'xx', '-'] # length 5
assert split_and_keep_delimiter('xx-xx-' ,'xx') == ['xx', '-', 'xx', '-'] # length 4
assert split_and_keep_delimiter('-xx-xx' ,'xx') == ['-', 'xx', '-', 'xx'] # length 4
assert split_and_keep_delimiter('xx-xx' ,'xx') == ['xx', '-', 'xx'] # length 3
assert split_and_keep_delimiter('xxxx' ,'xx') == ['xx', 'xx'] # length 2
assert split_and_keep_delimiter('xxx' ,'xx') == ['xx', 'x'] # length 2
assert split_and_keep_delimiter('x' ,'xx') == ['x'] # length 1
assert split_and_keep_delimiter('' ,'xx') == [] # length 0
assert split_and_keep_delimiter('aaa' ,'xx') == ['aaa'] # length 1
assert split_and_keep_delimiter('aa' ,'xx') == ['aa'] # length 1
assert split_and_keep_delimiter('a' ,'xx') == ['a'] # length 1
assert split_and_keep_delimiter('' ,'' ) == [] # length 0
assert split_and_keep_delimiter('a' ,'' ) == ['a'] # length 1
assert split_and_keep_delimiter('aa' ,'' ) == ['a', '', 'a'] # length 3
assert split_and_keep_delimiter('aaa' ,'' ) == ['a', '', 'a', '', 'a'] # length 5
"""
# Input assertions
assert isinstance(input,str), "input must be a string"
assert isinstance(delimiter,str), "delimiter must be a string"
if delimiter:
# These tokens do not include the delimiter, but are computed quickly
tokens = input.split(delimiter)
else:
# Edge case: if the delimiter is the empty string, split between the characters
tokens = list(input)
# The following assertions are always true for any string input and delimiter
# For speed's sake, we disable this assertion
# assert delimiter.join(tokens) == input
output = tokens[:1]
for token in tokens[1:]:
output.append(delimiter)
if token:
output.append(token)
# Don't let the first element be an empty string
if output[:1]==['']:
del output[0]
# The only case where we should have an empty string in the output is if it is our delimiter
# For speed's sake, we disable this assertion
# assert delimiter=='' or '' not in output
# The resulting strings should be combinable back into the original string
# For speed's sake, we disable this assertion
# assert ''.join(output) == input
return output
另一个在Python 3上工作良好的非正则表达式解决方案
# Split strings and keep separator
test_strings = ['<Hello>', 'Hi', '<Hi> <Planet>', '<', '']
def split_and_keep(s, sep):
if not s: return [''] # consistent with string.split()
# Find replacement character that is not used in string
# i.e. just use the highest available character plus one
# Note: This fails if ord(max(s)) = 0x10FFFF (ValueError)
p=chr(ord(max(s))+1)
return s.replace(sep, sep+p).split(p)
for s in test_strings:
print(split_and_keep(s, '<'))
# If the unicode limit is reached it will fail explicitly
unicode_max_char = chr(1114111)
ridiculous_string = '<Hello>'+unicode_max_char+'<World>'
print(split_and_keep(ridiculous_string, '<'))
另一个例子,在非字母数字上进行分割,并保留分隔符
import re
a = "foo,bar@candy*ice%cream"
re.split('([^a-zA-Z0-9])',a)
输出:
['foo', ',', 'bar', '@', 'candy', '*', 'ice', '%', 'cream']
解释
re.split('([^a-zA-Z0-9])',a)
() <- keep the separators
[] <- match everything in between
^a-zA-Z0-9 <-except alphabets, upper/lower and numbers.
安装wrs时“不拆卸分离器”
pip install wrs
(由Rao Hamza开发)
import wrs
text = "Now inbox “how to make spam ad” Invest in hard email marketing."
splitor = 'email | spam | inbox'
list = wrs.wr_split(splitor, text)
print(list)
结果: ['现在','收件箱'如何制作','垃圾广告'努力投资','电子邮件营销'。]
这里有一个简单的.split解决方案,不需要regex。
这是一个没有删除分隔符的Python split()的答案,所以不完全是最初的帖子所要求的,但另一个问题被关闭为这个问题的副本。
def splitkeep(s, delimiter):
split = s.split(delimiter)
return [substr + delimiter for substr in split[:-1]] + [split[-1]]
随机测试:
import random
CHARS = [".", "a", "b", "c"]
assert splitkeep("", "X") == [""] # 0 length test
for delimiter in ('.', '..'):
for _ in range(100000):
length = random.randint(1, 50)
s = "".join(random.choice(CHARS) for _ in range(length))
assert "".join(splitkeep(s, delimiter)) == s