如何使用正则表达式在（）中不存在|的情况下使用python |拆分字符串？

Question

嗨，我是新来的Python。你知道吗

我正在尝试使用正则表达式将字符串拆分为|，其中|在（）中不存在。但到目前为止没有运气。有什么建议吗？你知道吗

示例：

OUTPUT" "PROCEDURE" [ "IS" ] procedure-name [ ( "THROUGH" | "THRU" ) procedure-name ] | "GIVING" { file-name }+

上面的字符串应该分为两个字符串：

字符串1:OUTPUT" "PROCEDURE" [ "IS" ] procedure-name [ ( "THROUGH" | "THRU" ) procedure-name ]

字符串2:"GIVING" { file-name }+

Answer 1

对特定正则表达式模式使用re.split()函数：

import re

s = 'OUTPUT" "PROCEDURE" [ "IS" ] procedure-name [ ( "THROUGH" | "THRU" ) procedure-name ] | "GIVING" { file-name }+'
result = re.split(r'\|(?![^(]*\))', s)

print(result)  # the list, containing 2 strings

输出：

['OUTPUT" "PROCEDURE" [ "IS" ] procedure-name [ ( "THROUGH" | "THRU" ) procedure-name ] ', ' "GIVING" { file-name }+']

---

(?![^(]*\))-lookahead否定断言确保分隔符|后面没有右大括号)

[^(]-匹配除大括号外的任何字符(

\)-匹配右大括号)

Answer 2

展望[正面]：

re.split(r'(?<=] )\|',string)
Out[44]: 
['OUTPUT" "PROCEDURE" [ "IS" ] procedure-name [ ( "THROUGH" | "THRU" ) procedure-name ] ',
 ' "GIVING" { file-name }+']

Answer 3

新的^{} module支持的(*SKIP)(*FAIL)机制的一个很好的例子：

import regex as re

rx = re.compile(r'\([^)]*\)(*SKIP)(*FAIL)|\|')
string = """OUTPUT" "PROCEDURE" [ "IS" ] procedure-name [ ( "THROUGH" | "THRU" ) procedure-name ] | "GIVING" { file-name }+"""

parts = rx.split(string)
print(parts)
# ['OUTPUT" "PROCEDURE" [ "IS" ] procedure-name [ ( "THROUGH" | "THRU" ) procedure-name ] ', ' "GIVING" { file-name }+']

见a demo on regex101.com。你知道吗