如何删除python中的特定json值？

Question

我正在制作一个播放列表网站，可以创建、显示和删除播放列表和歌曲。我使用一个JSON文件来存储数据。唯一不起作用的功能是删除歌曲功能。

这是我的JSON文件

"Playlists": [
    {
        "ID": 1,
        "Name": "Car Boosted",
        "Songs": [
            {
                "Name": "Dusk Till Dawn",
                "Artist": "Sia",
                "Link": "https://www.youtube.com/watch?v=6ADdqsvlqtU"
            },
            {
                "Name": "Blinding Lights",
                "Artist": "The Weekend",
                "Link": "https://www.youtube.com/watch?v=4NRXx6U8ABQ"
            }
        ],
        "Date": "16 / 03 / 2022"
    },
    {
        "ID": 2,
        "Name": "Workout Playlists",
        "Songs": [
            {
                "Name": "Dusk Till Dawn",
                "Artist": "Sia",
                "Link": "https://www.youtube.com/watch?v=6ADdqsvlqtU"
            },
            {
                "Name": "Blinding Lights",
                "Artist": "The Weekend",
                "Link": "https://www.youtube.com/watch?v=4NRXx6U8ABQ"
            },
            {
                "Name": "Till I Collapes",
                "Artist": "Eminem",
                "Link": "https://www.youtube.com/watch?v=Obim8BYGnOE"
            },
            {
                "Name": "Lose Yourself",
                "Artist": "Eminem",
                "Link": "https://www.youtube.com/watch?v=_Yhyp-_hX2s"
            }
        ],
        "Date": "25 / 04 / 2022"
    }
]

我使用播放列表的ID和歌曲的索引来找到它在列表中的位置，并使用它来删除它。这是我的"deleteSong“函数：

def deleteSongFromJson(songID, pid):
"""deletes Songs Form Playlist

Args:
        songID (int): ID Of Song
        id (itn): ID Of Playlist
"""
pid = int(pid)
songID = int(songID)
with open('databse.json','r+') as file:
    data = json.load(file)
    playlists = data['Playlists']
    for playlist in playlists:
     if playlist['ID'] == id:
         songs = playlist["Songs"]
         del songs[songID]
         file.seek(0)
         json.dump(data, file, indent = 4)

当我运行这个函数时，它会从右边的播放列表中删除歌曲，但是会粘贴列表的最后一部分，然后粘贴到JSON文件的底部。

例如。

                "Name": "Blinding Lights",
                "Artist": "The Weekend",
                "Link": "https://www.youtube.com/watch?v=4NRXx6U8ABQ"
            }
        ],
        "Date": "17 / 05 / 2022"
    }
]
    "Artist": "The Weekend",
                "Link": "https://www.youtube.com/watch?v=4NRXx6U8ABQ"
            }
        ],
        "Date": "17 / 05 / 2022"
    }
]

Answer 1

我认为您的问题是尝试一次读取和写入文件，这可能会导致奇怪的光标问题。

尝试重构您的代码，以便有两个独立的open语句，如下所示(未经测试)：

def deleteSongFromJson(songID, pid):
    """deletes Songs from Playlist

    Args:
        songID (int): ID Of Song
        id (itn): ID Of Playlist
    """
    pid = int(pid)
    songID = int(songID)

    with open('databse.json','r') as file:
        data = json.load(file)

    for playlist in data['Playlists']:
        if playlist['ID'] == id:
            del playlist["Songs"][songID]

    with open('databse.json','w') as file:
        json.dump(data, file, indent=4)