python - 从现有词典创建频率词典

Question

我有一个名为播放列表的字典，其条目格式为:

{datetime.datetime(2019, 11, 4, 20, 2): ('Wagon Wheel', 'Darius Rucker'), 
datetime.datetime(2019, 11, 4, 19, 59): ('Remember You Young', 'Thomas Rhett'), 
datetime.datetime(2019, 11, 4, 19, 55): ('Long Hot Summer', 'Keith Urban')}

我想迭代这个字典来构造一个新的字典song_count，其中每首歌曲的名称作为键，其计数/频率作为值。这是到目前为止我所拥有的代码。

song_count = {}
for song in playlist:
    if playlist[song] in song_count:
        song_count[playlist[song]].append(song)
    else:
        song_count[playlist_[song]]=[song]
print(song_count)

但是，这无法将歌曲与调中的艺术家分开，也不会创建计数作为值。

新词典应如下所示:

{'Wagon Wheel-Darius Rucker': 1, 
'Remember You Young-Thomas Rhett': 7, 
'Long Hot Summer-Keith Urban': 1, … }

Answer 1

尝试对您的代码进行以下修改:

# Initialise new dictionary
song_count = dict()

# For each entry in the playlist dict
for song in playlist.values():
    # Convert the tuple to song-artist string
    song_name = '-'.join(song)

    # If already in the dictionary, add 1 to the count
    if song_name in song_count:
        song_count[song_name] += 1

    # Otherwise set the count to 1
    else:
        song_count[song_name] = 1
print(song_count)

输出:

{'Wagon Wheel-Darius Rucker': 1, 'Remember You Young-Thomas Rhett': 1, 'Long Hot Summer-Keith Urban': 1}