使用 Python 列表组织 JSON 文件的结果？

Question

我已经解析了一个 JSON 文件，其中包含大约 3000 首歌曲的曲目名称和专辑名称，但尝试将其组织成列表或类似的列表时却一无所获？

我基本上想将这些项目分类到一个唯一专辑列表中，每个专辑都包含一个曲目列表，并且想知道这是否真的可能，因为我不知道如何为列表分配名称？

到目前为止我的代码如下：

import json
from pprint import pprint

with open('.../playlist.json', encoding="utf-8") as f:
    data = json.load(f)

for playlist in data['playlists']:
    if playlist['name'] == 'PLAYLIST3':
        for item in playlist['items']:
            track = item['track']['trackName']
            album = item['track']['albumName']

此外，歌曲没有以任何特定方式排序。

编辑： 这就是我所做的，它似乎在创建一个以歌曲列表为值、专辑名称为键的字典列表时效果很好：

import json
from pprint import pprint

with open('C:/Users/nambi/Desktop/parse/playlist.json', encoding="utf-8") as f:
    data = json.load(f)

listOfAlbums = {}

for playlist in data['playlists']:
    if playlist['name'] == 'P4':
        for item in playlist['items']:
            title = item['track']['trackName']
            album = item['track']['albumName']

            if album in listOfAlbums:
                listOfAlbums[album].append(title)
            else:
                listOfAlbums[album] = [title]

Answer 1

您可以只使用 collections.defaultdict 因为它允许设置每个键的值的类型。 在您的情况下，键是专辑名称，值是曲目列表。

import json
from collections import defaultdict
from pprint import pprint

with open('.../playlist.json', encoding="utf-8") as f:
    data = json.load(f)

result = defaultdict(list)
for playlist in data['playlists']:
    if playlist['name'] != 'PLAYLIST3':
        continue

    for item in playlist['items']:
        track = item['track']['trackName']
        album = item['track']['albumName']
        result[album].append(track)

编辑：其他改进：

import json
from collections import defaultdict
from itertools import ifilter
from pprint import pprint

with open('.../playlist.json', encoding="utf-8") as f:
    data = json.load(f)

result = defaultdict(list)
for playlist in ifilter(lambda p: p['name'] == 'PLAYLIST3', data['playlists']):
    for item in playlist['items']:
        track = item['track']['trackName']
        album = item['track']['albumName']
        result[album].append(track)

Answer 2

如果您想将歌曲分类到包含歌曲列表的独特专辑中，下面的代码应该可以完成工作。 结果是dict 到歌曲list；如果曲目不是专辑，它会忽略它，如果专辑在res 中不存在，它会创建它。

results = {}
for playlist in data['playlists']:
    # if playlist['name'] == 'PLAYLIST3':
    if 'items' in playlist:
        for item in playlist['items']:
            # extract data 
            track_name = item['track']['trackName']
            album = item['track']['albumName']
            # create album in results if not exist
            # if the album names are not following the same typo, normalize them here 
            # like album = album.lower()
            if album not in results:
                results[album] = []
            # if track is not once inserted in album insert it
            if track_name not in results[album]:
                results[album].append(track_name)
# use results as you wish
print(results)