Python 9.3.1 self.py课程-分拣文件数据的简单程序-dosent工作

在包含故障警告的txt文件上：

Tudo Bom;Static and Ben El Tavori;5:13;
I Gotta Feeling;The Black Eyed Peas;4:05;
Instrumental;Unknown;4:15;
Paradise;Coldplay;4:23;
Where is the love?;The Black Eyed Peas;4:13;

我正在尝试使用这个简单的程序：

def my_mp3_playlist(file_path):
    with open(file_path, 'r') as playlist_file:
        result_playlist_tuple = tuple()  # Result tuple
        playlist_splitted_lines = playlist_file.readlines()#.split("\n")  # List of songs and additional data
        len_of_playlist_splitted_lines = len(playlist_splitted_lines)  # Getting list length instead of running a
        # loop len(x) times
        playlist_items = list()
        for line in range(len_of_playlist_splitted_lines):  # Extracting list of items from list of lines
            playlist_items.append(playlist_splitted_lines[line].split(';'))
        for element in playlist_items:  # Deleting empty strings '' in playlist_lines
            del element[-1]
            del playlist_items[-1]
        max_song_length, longest_song_name = 0, ""
        max_artist_appearances, most_appearing_artist = 0, ""
        for i in playlist_items:
            # Getting max song length
            curr_float_song_length = float(i[-1].replace(':', '.'))
            if curr_float_song_length > max_song_length:  # Getting max song length
                max_song_length = curr_float_song_length
                longest_song_name = i[0]
            if i.count(i[1]) > max_artist_appearances:  # Getting Most appearing song
                max_artist_appearances = playlist_items.count(i)
                most_appearing_artist = i[1]
        result_playlist_tuple += (longest_song_name, len(playlist_items), most_appearing_artist)
        return result_playlist_tuple
 
 
def main():
    file_path = input("Enter file path: ")
    print(my_mp3_playlist(file_path))
 
 
if __name__ == '__main__':
    main()

      

程序需要返回元组：（str:longest\u歌曲，int:playlist\u项目（行），str:most\u艺术家）

我想要的输出：（“土豆条”，5，“黑眼豌豆”）

我得到的结果是：（'Tudo Bom'，3'，Static和Ben El Tavori'）*

请帮忙， 谢谢你，

---

Eyal.

我想可能是关于这条线路的

        del playlist_items[-1]

---

您可能试图删除最后一行，但您正在删除播放列表项目列表中的每一行。

正如@JMCampos已经回答的那样，对于播放列表中的每一个元素，您将删除列表中最新的元素：

for element in playlist_items:
    del element[-1]
    del playlist_items[-1]

因此，您的项目列表将减半，只包含3行，而不是5行。您需要从循环中删除此行，如下所示：

del playlist_items[-1]
for element in playlist_items:
    del element[-1]

playlist_items = [item for item in playlist_items if item]

但确保您拥有非空数据的更具python风格的方法是这样使用：

del playlist_items[-1]
for element in playlist_items:
    del element[-1]

playlist_items = [item for item in playlist_items if item]

第三个结果参数是最常见的艺术家。您尝试在一条始终为1的直线上计算艺术家出现的次数。检查后，您计算最大外观数作为列表中整行的外观数（也始终为1，因为文件中没有重复的行）：

有几种方法可以从列表中获取最频繁的值。例如，您可以在字典中收集您的艺术家及其歌曲数量，然后获得数量最高的艺术家：

artists = {}
for item in playlist_items:
    artist = item[1]
    if artist not in artists:
        artists[artist] = 0
    artists[artist] += 1
most_appearing_artist, number_of_appearances = max(artists.items(), key=lambda x: x[1])