从两个嵌套的dictionaries
开始:
p1 = {'user1': {u'Codex': 1.0, u'High And Dry': 1.0, u'Hey': 1.0, u'O': 1.0, u'Videotape': 1.0, u'Pyramid Song': 1.0}}
和
p2 = {'user1': {u'Codex': 1.0, u'High And Dry': 1.0, u'Hey': 1.0, u'O': 1.0, u'Videotape': 1.0, u'Pyramid Song': 1.0,
u'x': 1.0, u'y': 1.0, u'w': 1.0, u'z': 1.0}}
我正在获取两个外部keys
playlist1 = p1['user1'].keys()
playlist2 = p2['user1'].keys()
为了定义一个增量function
,其目的是增加重复歌曲的计数,并保持所有其他歌曲不受影响,我写道:
def incremented_playlist(playlist1, playlist2):
playlist3 = {'user1':{}}
for song in playlist2:
if song in playlist1:
playlist3['user1'][song] = 2.0
else:
playlist3['user1'][song] = 1.0
return playlist3
打印示例所需的output
:
print incremented_playlist(playlist1, playlist2)
即{'user1': {u'Pyramid Song': 2.0, u'Videotape': 2.0, u'High And Dry': 2.0, u'Hey': 2.0, u'O': 2.0, u'Codex': 2.0, u'w': 1.0, u'y': 1.0, u'x': 1.0, u'z': 1.0}}
,但我如何建立一个增量部分,现在只有值分配?
是否有built-in
python
class
比increment
更好?
这样的东西应该工作,如果我理解正确的话。您有2个播放列表,并希望在不同的播放列表中做出评级的总和。因此,如果我在两个播放列表中都给了一些评分为1的歌曲,那么总和将是2,如果我只给了其中一个,那么总和将是1。如果有不同于1的评级,这个解决方案也会起作用。
p1 = {'user1': {u'Codex': 1.0, u'High And Dry': 1.0, u'Hey': 1.0, u'O': 1.0, u'Videotape': 1.0, u'Pyramid Song': 1.0}}
p2 = {'user1': {u'Codex': 1.0, u'High And Dry': 1.0, u'Hey': 1.0, u'O': 1.0, u'Videotape': 1.0, u'Pyramid Song': 1.0,
u'x': 1.0, u'y': 1.0, u'w': 1.0, u'z': 1.0}}
total = dict()
for user, ratings in p1.items():
this_user_ratings = ratings
if user in p2:
ratings2 = p2[user]
for k, v in ratings2.items():
this_user_ratings[k] = this_user_ratings.get(k, 0) + v
total[user] = this_user_ratings
print(total)
或者如果你需要一个解决方案,将工作与任意数量的字典(播放列表),你可能想要使用这样的东西:
all_playlists = [p1, p2]
total = dict()
for playlist in all_playlists:
for user, ratings in playlist.items():
total.setdefault(user, dict())
for k, v in ratings.items():
total[user][k] = total[user].get(k, 0) + v