如何使用 ElementTree 访问 iTunes xml 中的值元素？

Question

我正在尝试从 xml 播放列表“导出”到 html 表以进行共享。但是 iTunes 库文件使用键值对而不是更有意义的 XML 标签。是否有一种简单的方法也可以获取<value>这些键/值对？这让我得到了 的值<key>，即 Track ID Name Artist Album Artist 等，但我似乎无法找到一种方法来获取下一个键的值，即<integer>49924 或<string>Ep。35 | 你做什么......我可以（应该）用 ElementTree 来做这件事还是我应该继续使用正则表达式或其他一些库？谢谢！data = '''<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"><plist version="1.0"><dict>    <key>Major Version</key><integer>1</integer>    <key>Minor Version</key><integer>1</integer>    <key>Date</key><date>2019-01-21T07:31:15Z</date>    <key>Application Version</key><string>12.8.0.150</string>    <key>Features</key><integer>5</integer>    <key>Show Content Ratings</key><true/>    <key>Music Folder</key><string>file:///Users/Music/iTunes/iTunes%20Media/</string>    <key>Library Persistent ID</key><string>75E62CF156F5AE1B</string>    <key>Tracks</key>    <dict>        <key>49924</key>        <dict>            <key>Track ID</key><integer>49924</integer>            <key>Name</key><string>Ep. 35 | What Do Your Morals Taste Like? | Guest: Jonathan Haidt</string>            <key>Artist</key><string>Blaze Podcast Network</string>            <key>Album Artist</key><string>Blaze Podcast Network</string>            <key>Album</key><string>Something's Off with Andrew Heaton</string>            <key>Genre</key><string>News &#38; Politics</string>            <key>Kind</key><string>MPEG audio file</string>            <key>Size</key><integer>48123940</integer>            <key>Total Time</key><integer>3004133</integer>            <key>Year</key><integer>2019</integer>            <key>Date Modified</key><date>2019-01-13T01:10:30Z</date>            <key>Date Added</key><date>2019-01-13T01:10:30Z</date>            <key>Bit Rate</key><integer>128</integer>

Answer 1

问题：如何访问 iTunes xml 中的值元素

以下解决方案使用lxml.etree.iterparse附加<key>带有以下<value>标签的标签来构建 Python dict {key:value}.

使用的模块和内置函数：

• lxml.etree.iterparse

• object.__iter__(self)

• 收益声明

from lxml import etree

import io

class Playlist:

    def __init__(self, fh):

        """

        Initialize 'iterparse' to generate 'start' and 'end' events on all tags

        :param fh: File Handle from the XML File to parse

        """

        self.context = etree.iterparse(fh, events=("start", "end",))

    def _parse(self):

        """

        Yield only at 'end' event, except 'start' from tag 'dict'

        :return: yield current Element

        """

        for event, elem in self.context:

            if elem.tag == 'plist' or \

                    (event == 'start' and not elem.tag == 'dict'):

                continue

            yield elem

    def _parse_key_value(self, key=None):

        _dict = {}

        for elem in self._parse():

            if elem.tag == 'key':

                key = elem.text

                continue

            if elem.tag in ['integer', 'string', 'date']:

                if not key is None:

                    _dict[key] = elem.text

                    key = None

                else:

                    print('Missing key for value {}'.format(elem.text))

            elif elem.tag in ['true', 'false']:

                _dict[key] = elem.tag == 'true'

            elif elem.tag == 'dict':

                if not key is None:

                    _dict[key] = self._parse_dict(key)

                    key = None

                else:

                    return elem, _dict

            else:

                print('Unknow tag {}'.format(elem.tag))

    def _parse_dict(self, key=None):

        elem = next(self._parse())

        elem, _dict = self._parse_key_value(elem.text)

        return _dict

    def __iter__(self):

        for elem in self._parse():

            if elem.tag == 'dict':

                yield self._parse_dict()

            else:

                print('Unknow tag {}'.format(elem.tag))

if __name__ == "__main__":

    data = b'''<?xml...'''

    with io.BytesIO(data) as in_xml:

        for record in Playlist(in_xml):

            print("record:{}".format(record))

            for key, value in record.items():

                print("{}:{}".format(key, value))

输出：

record:{'Major Version': '1', 'Minor Version': '1'... (omitted for brevity)

    Major Version:1

    Minor Version:1

    Date:2019-01-24T10:31:15Z

    Tracks:{'99244': {'Track ID': '99244', 'Artist': 'Blaze Podcast Network', ... (omitted for brevity)}}

用 Python 测试：3.5