charts.py 文件源码

def top_yearly_artists():
    scrobbles = func.count(Scrobble.artist).label('count')
    charts = {}

    col_year = func.extract('year', Scrobble.played_at)
    year_from, year_to = db.session.query(func.min(col_year), func.max(col_year)).first()
    year_from, year_to = int(year_from), int(year_to)

    stat_count = 1000
    show_count = 100

    for year in range(year_from, year_to + 1):
        time_from = datetime.datetime(year, 1, 1)
        time_to = datetime.datetime(year, 12, 31, 23, 59, 59, 999999)
        charts[year] = (
            db.session.query(Scrobble.artist, scrobbles)
            .filter(Scrobble.user_id == current_user.id)
            .filter(Scrobble.played_at >= time_from, Scrobble.played_at <= time_to)
            .group_by(Scrobble.artist)
            .order_by(scrobbles.desc())
            .limit(stat_count)
            .all()
        )

    position_changes = {}

    for year in range(year_from + 1, year_to + 1):
        chart = {artist: position for position, (artist, scrobbles) in enumerate(charts[year], 1)}
        prev_chart = {
            artist: position for position, (artist, scrobbles) in enumerate(charts[year - 1], 1)
        }

        prev_charts = (chart for chart_year, chart in charts.items() if chart_year < year)
        prev_artists = {artist for chart in prev_charts for (artist, scrobbles) in chart}

        if year not in position_changes:
            position_changes[year] = {}

        for artist, data in chart.items():
            if artist in prev_chart:
                position_changes[year][artist] = prev_chart[artist] - chart[artist]
            elif artist not in prev_artists:
                position_changes[year][artist] = 'new'

    charts = sorted(charts.items())

    return render_template(
        'charts/top_yearly_artists.html',
        charts=charts,
        position_changes=position_changes,
        show_count=show_count
    )