__str __（self）返回合适的专辑字符串表示形式

Question

我这里有两节课。在我的课堂相册中，我的 str 功能无效，因为我只能返回其中一个专辑详情。 测试：

t1 = Track('Bicyclops', 'Bela Fleck', 260)
t3 = Track('Watch What Happens', 'Frank Sinatra', 200)
album1 = Album('My Way', 'Frank Sinatra', '1969', [t1, t3])
print(album1)

它返回的内容My Way by Frank Sinatra (1969)

但我希望它能够回归 My Way by Frank Sinatra (1969) Track: Bicyclops by Bela Fleck (260) Track: Watch What Happens by Frank Sinatra (200)

我知道我需要创建一个单独的函数并在 str 中调用它，但我不知道如何处理它。我已经创建了额外的功能track_list但不是100％肯定。这是一个很长的问题，但这是我能用最好的方式解释它的唯一方法。

class Track: 

def __init__(self, title, artist,duration): 
    self.artist = artist 
    self.title = title 
    self.duration = duration 

def __repr__(self): 
    return 'Track(' + str(self.artist) + ", " +  str(self.title) + ", " + str(self.duration) + ')'

def __str__(self): 
    return "Track: " + str(self.title) + " by " + str(self.artist) + " (" + str(self.duration) + ")" 

def get_artist(self):
    return self.artist 

def get_title(self): 
    return self.title 

def get_duration(self): 
    return self.duration 

class Album：

def __init__(self, title, artist, year, list_of_tracks): 
    self.artist = artist 
    self.title = title 
    self.year = year
    self.list_of_tracks = list_of_tracks 

def __repr__(self): 
    return 'Album(' + str(self.artist) + ", " + str(self.title) + ", " + str(self.year) + ')'

def track_list(self,artist,title,duration): 
    track1 =  "Track: " + str(self.title) + " by " + str(self.artist) + " (" + str(self.duration) + ")" 
    track2 =  "Track: " + str(self.title) + " by " + str(self.artist) + " (" + str(self.duration) + ")" 
    return track1, track2 

def __str__(self): 
    return str(self.title) + " by " + str(self.artist) + " (" + str(self.year) + ")"

Answer 1

试试这个，

class Album:
   ..............
   def __str__(self):  
    return str(self.title) + " by " + str(self.artist) + " (" + str(self.year) + ")"+str(self.list_of_tracks)

如果你想要分开的话，

方法1：

class Album:
   ..............
 def __str__(self):  
    tempStr=''
    for item in self.list_of_tracks: 
        tempStr += '\n'+str(item);
    return str(self.title) + " by " + str(self.artist) + " (" + str(self.year) + ")"+tempStr