拆分唯一字符串 - Python

Question

我正在尝试找到解析此类字符串的最佳方法：

Operating Status: NOT AUTHORIZED Out of Service Date: None

我需要这样的输出：

['Operating Status: NOT AUTHORIZED', 'Out of Service Data: None']

有没有简单的方法可以做到这一点？我正在像这样解析数百个字符串。没有确定性文本，但它始终采用上述格式。

其他字符串示例：

MC/MX/FF Number(s): None  DUNS Number: -- 
Power Units: 1  Drivers: 1

预期输出：

['MC/MX/FF Number(s): None, 'DUNS Number: --']
['Power Units: 1,  Drivers: 1 ']

Answer 1

有两种方法。两者都非常笨拙，并且极度依赖于原始字符串中非常小的波动。但是，您可以修改代码以提供更多的灵活性。

这两个选项都取决于满足这些特征的线路... 有问题的分组必须...

以字母或斜杠开头，可能大写
感兴趣的标题后跟一个冒号（“:”）
只抓取冒号后的第一个单词。

方法一，regex，这个只能抓取两块数据。第二组是 "everything else" 因为我无法让搜索模式正确重复 :P

代码：

import re

l = [ 'MC/MX/FF Number(s): None DUNS Number: -- ', 'Power Units: 1 Drivers: 1 ' ]

pattern = ''.join([
                 "(", # Start capturing group  
                 "\s*[A-Z/]", # Any number of space, until and including only the first capital or forward slash 
                 ".+?\:", # any character (non-greedy) up to and including the colon
                 "\s*", # One or more spaces
                 "\w+\s*", # One or more alphanumeric chars i.e. [a-zA-Z0-9]
                  ")", # End capturing group
                  "(.*)"
])

for s in l: 
    m = re.search(pattern, s)
    print("----------------")
    try:
        print(m.group(1))
        print(m.group(2))
        print(m.group(3))
    except Exception as e:
        pass

输出：

----------------
MC/MX/FF Number(s): None 
DUNS Number: -- 
----------------
Power Units: 1 
Drivers: 1

方法二，逐字解析字符串。该方法与正则表达式的基本特征相同，但可以做两个以上感兴趣的块。它的工作原理...

开始逐字解析每个字符串，并将其加载到 newstring.
遇到冒号时，标记一个标志。
将下一个循环的第一个单词添加到 newstring。如果需要，您可以将其更改为 1-2、1-3 或 1-n 字。您也可以让它在设置 colonflag 之后继续添加单词，直到满足某些条件，例如带有大写字母的单词……尽管这可能会中断 "None." 之类的单词您可以一直持续到一个单词满足所有大写字母，但是 not-all-capital header 会破坏它。
将newstring添加到newlist，重置标志，并继续解析单词。

代码：

s =     'MC/MX/FF Number(s): None DUNS Number: -- ' 
for s in l: 
    newlist = []
    newstring = ""
    colonflag = False
    for w in s.split():
        newstring += " " + w
        if colonflag: 
            newlist.append(newstring)
            newstring = ""
            colonflag = False

        if ":" in w:
            colonflag = True
    print(newlist)

输出：

[' MC/MX/FF Number(s): None', ' DUNS Number: --']
[' Power Units: 1', ' Drivers: 1']

第三个选项： 创建一个包含所有预期的 header 的列表，例如 header_list = ["Operating Status:", "Out of Service Date:", "MC/MX/FF Number(s):", "DUNS Number:", "Power Units:", "Drivers:", ]，并根据这些列表创建 split/parse。

第四个选项

使用 Natural Language Processing 和机器学习来实际找出逻辑句子的位置 ;)

Answer 2

看看pyparsing。这似乎是表达单词组合、检测它们之间的关系（语法上）并生成结构化响应的最 'natural' 方式……网上有大量教程和文档：

您可以使用“pip install pyparsing”安装 pyparsing

正在解析：

Operating Status: NOT AUTHORIZED Out of Service Date: None

需要这样的东西：

!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
#  test_pyparsing2.py
#
#  Copyright 2019 John Coppens <john@jcoppens.com>
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#
#

import pyparsing as pp

def create_parser():
    opstatus = pp.Keyword("Operating Status:")
    auth     = pp.Combine(pp.Optional(pp.Keyword("NOT"))) + pp.Keyword("AUTHORIZED")
    status   = pp.Keyword("Out of Service Date:")
    date     = pp.Keyword("None")

    part1    = pp.Group(opstatus + auth)
    part2    = pp.Group(status + date)

    return part1 + part2



def main(args):
    parser = create_parser()

    msg = "Operating Status: NOT AUTHORIZED Out of Service Date: None"
    print(parser.parseString(msg))

    msg = "Operating Status: AUTHORIZED Out of Service Date: None"
    print(parser.parseString(msg))

    return 0

if __name__ == '__main__':
    import sys
    sys.exit(main(sys.argv))

运行程序：

[['Operating Status:', 'NOT', 'AUTHORIZED'], ['Out of Service Date:', 'None']]
[['Operating Status:', '', 'AUTHORIZED'], ['Out of Service Date:', 'None']]

使用 Combine 和 Group 您可以更改输出的组织格式。

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