如何在Django中按多字段排序对象并分碟展示音乐专辑曲目？

Got it, let's get your multi-disc album tracks showing in the format you want. Here's a straightforward way to do it using Django's built-in template tags and a small adjustment to your view.

Step 1: Update the View to Sort Tracks by Disc First #

First, we need to make sure our tracks are ordered by disc number (and then track number) so we can group them correctly in the template. Modify your view code like this:

def music_album_detail(request, pk):
    music_album = get_object_or_404(MusicAlbums, pk=pk)
    # Order by disc first, then track number to ensure proper grouping
    music_album_tracks = MusicTracks.objects.filter(album=music_album).order_by('disc', 'track')
    args = {
        'music_album': music_album,
        'music_album_tracks': music_album_tracks,
    }
    return render(request, 'App/music_album_detail.html', args)

Step 2: Use Django's regroup Tag in the Template #

Now, use Django's {% regroup %} template tag to group tracks by their disc number. Then loop through each disc group to display the disc label followed by the track names separated by " - ".

Replace your existing template loop with this:

{% regroup music_album_tracks by disc as disc_groups %}

{% for disc_group in disc_groups %}
    <p>
        {# Handle cases where disc number might be null (default to 1) #}
        碟{{ disc_group.grouper|default:1 }}
        {% for track in disc_group.list %}
            {% if not forloop.first %} - {% endif %}
            {{ track.title }}
        {% endfor %}
    </p>
{% endfor %}

How This Works: #

• {% regroup ... %} takes your sorted track list and groups them by the disc field, creating a list of groups where each group has a grouper (the disc number) and a list of tracks in that disc.
• The |default:1 filter ensures that any tracks with no disc number set will be grouped under "碟1".
• The inner loop adds " - " before each track except the first one, giving you the exact format you want.

Example Output: #

If you have 2 discs with 4 tracks each, this will render:

碟1 - 曲目名1 - 曲目名2 - 曲目名3 - 曲目名4
碟2 - 曲目名1 - 曲目名2 - 曲目名3 - 曲目名4

Alternative: Group in the View with itertools.groupby #

If you prefer to handle grouping in the view instead of the template, you can use Python's itertools.groupby. Here's how:

Update your view:

from itertools import groupby
from operator import attrgetter

def music_album_detail(request, pk):
    music_album = get_object_or_404(MusicAlbums, pk=pk)
    tracks = MusicTracks.objects.filter(album=music_album).order_by('disc', 'track')
    # Group tracks by disc number
    disc_groups = []
    for disc_num, track_group in groupby(tracks, key=attrgetter('disc')):
        disc_groups.append({
            'disc_number': disc_num or 1,
            'tracks': list(track_group)
        })
    args = {
        'music_album': music_album,
        'disc_groups': disc_groups,
    }
    return render(request, 'App/music_album_detail.html', args)

Then your template becomes simpler:

{% for disc in disc_groups %}
    <p>
        碟{{ disc.disc_number }}
        {% for track in disc.tracks %}
            {% if not forloop.first %} - {% endif %}
            {{ track.title }}
        {% endfor %}
    </p>
{% endfor %}

Either approach will work—pick whichever you find more readable!

内容的提问来源于stack exchange，提问作者user16837137