Split string with multiple delimiters in Python [duplicate]

问题

This question already has an answer here:

Split Strings into words with multiple word boundary delimiters 31 answers

I found some answers online, but I have no experience with regular expressions, which I believe is what is needed here.

I have a string that needs to be split by either a \';\' or \', \' That is, it has to be either a semicolon or a comma followed by a space. Individual commas without trailing spaces should be left untouched

Example string:

\"b-staged divinylsiloxane-bis-benzocyclobutene [124221-30-3], mesitylene [000108-67-8]; polymerized 1,2-dihydro-2,2,4- trimethyl quinoline [026780-96-1]\"

should be split into a list containing the following:

(\'b-staged divinylsiloxane-bis-benzocyclobutene [124221-30-3]\' , \'mesitylene [000108-67-8]\', \'polymerized 1,2-dihydro-2,2,4- trimethyl quinoline [026780-96-1]\')

回答1:

Luckily, Python has this built-in :)

import re
re.split('; |, ',str)

Update:
Following your comment:

>>> a='Beautiful, is; better*than\nugly'
>>> import re
>>> re.split('; |, |\*|\n',a)
['Beautiful', 'is', 'better', 'than', 'ugly']

回答2:

Do a str.replace('; ', ', ') and then a str.split(', ')

回答3:

Here's a safe way for any iterable of delimiters, using regular expressions:

>>> import re
>>> delimiters = "a", "...", "(c)"
>>> example = "stackoverflow (c) is awesome... isn't it?"
>>> regexPattern = '|'.join(map(re.escape, delimiters))
>>> regexPattern
'a|\\.\\.\\.|\\(c\\)'
>>> re.split(regexPattern, example)
['st', 'ckoverflow ', ' is ', 'wesome', " isn't it?"]

re.escape allows to build the pattern automatically and have the delimiters escaped nicely.

Here's this solution as a function for your copy-pasting pleasure:

def split(delimiters, string, maxsplit=0):
    import re
    regexPattern = '|'.join(map(re.escape, delimiters))
    return re.split(regexPattern, string, maxsplit)

If you're going to split often using the same delimiters, compile your regular expression beforehand like described and use RegexObject.split.

回答4:

In response to Jonathan's answer above, this only seems to work for certain delimiters. For example:

>>> a='Beautiful, is; better*than\nugly'
>>> import re
>>> re.split('; |, |\*|\n',a)
['Beautiful', 'is', 'better', 'than', 'ugly']

>>> b='1999-05-03 10:37:00'
>>> re.split('- :', b)
['1999-05-03 10:37:00']

By putting the delimiters in square brackets it seems to work more effectively.

>>> re.split('[- :]', b)
['1999', '05', '03', '10', '37', '00']

回答5:

This is how the regex look like:

import re
# "semicolon or (a comma followed by a space)"
pattern = re.compile(r";|, ")

# "(semicolon or a comma) followed by a space"
pattern = re.compile(r"[;,] ")

print pattern.split(text)

来源：https://stackoverflow.com/questions/4998629/split-string-with-multiple-delimiters-in-python

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python

string

split

delimiter