def add(self, entity):
"""Add entity to repository. If there is a song with entity's title and author ValueError will be raised."""
with open(self._filename, "r") as file:
for line in file:
song = Song("", "", "", "").from_string(line.strip())
if song.get_artist() == entity.get_artist() and \
song.get_title() == entity.get_title():
raise ValueError("Song already exists")
with open(self._filename, "a") as file:
file.write("{}\n".format(entity.to_string()))
def generate_songs(self, dto):
"""
Generate dto random songs and add them to the repository. dto must be a positive integer as string.
dto="number"
"""
if int(dto) < 1:
raise ValueError("Invalid number")
def random_chr(j):
v = ["a", "e", "i", "o", "u"]
c = [
"b", "c", "d", "f", "g", "h", "j", "k", "l", "m", "n", "p",
"q", "r", "s", "t", "w", "x", "y", "z"
]
return v[trunc(random() *
len(v))] if j % 2 == 0 else c[trunc(random() *
len(c))]
genres = ["Rock", "Pop", "Jazz", "Altele"]
for i in range(int(dto)):
artist_len1 = trunc(random() * 8 + 1)
artist_len2 = trunc(random() * 8 + 1)
title_len1 = trunc(random() * 16 + 1)
title_len2 = trunc(random() * 16 + 1)
artist = "".join([random_chr(i)
for i in range(artist_len1)] + [" "] +
[random_chr(i) for i in range(artist_len2)])
title = "".join([random_chr(i) for i in range(title_len1)] +
[" "] + [random_chr(i) for i in range(title_len2)])
duration = trunc(random() * 500)
genre = genres[trunc(random() * len(genres))]
song = Song(title, artist, genre, duration)
self._repository.add(song)
def test_add():
remove("test_repo.txt")
repository = SongFileRepository("test_repo.txt")
repository.add(Song("a", "b", "c", "d"))
with open("test_repo.txt", "r") as file:
line = file.readline().strip()
assert line == "b,a,d,c"
def get(self, playlist_id: int) -> Playlist:
cursor = self.database_connector.cursor()
query = "SELECT * FROM Playlists WHERE playlist_id = %s"
cursor.execute(query, (playlist_id, ))
results = cursor.fetchone()
if results is None:
cursor.close()
raise PlaylistNotFound()
playlist_id, title = results
playlist = Playlist()
playlist.playlist_id = playlist_id
playlist.title = title
query = "SELECT user_id FROM Users_Playlists WHERE playlist_id = %s"
cursor.execute(query, (playlist_id, ))
user_id, = cursor.fetchone()
playlist.user_id = user_id
query = "SELECT s.song_id, s.album_id, s.artist_id, s.title, s.duration FROM Songs s, Playlist_Songs ps WHERE " \
"s.song_id = ps.song_id AND ps.playlist_id = %s"
cursor.execute(query, (playlist_id, ))
for (song_id, album_id, artist_id, title, duration) in cursor:
song = Song()
song.song_id = song_id
song.artist_id = artist_id
song.album_id = album_id
song.title = title
song.duration = duration
playlist.songs.append(song)
for song in playlist.songs:
query = "SELECT artist_name FROM Artists WHERE artist_id = %s"
cursor.execute(query, (song.artist_id, ))
artist_name, = cursor.fetchone()
song.artist_name = artist_name
for song in playlist.songs:
query = "SELECT title FROM Albums WHERE album_id = %s"
cursor.execute(query, (song.album_id, ))
title, = cursor.fetchone()
song.album_name = title
cursor.nextset()
cursor.close()
return playlist
def get_all(self):
"""Return a list of all the songs as Song instances."""
result = []
with open(self._filename, "r") as file:
for line in file:
song = Song("", "", "", "").from_string(line.strip())
result.append(song)
return result
def add_song(self, dto):
"""
Convert dto to song and add it to repository after successful validation.
If there is already a song with the artist-title combination in dto ValueError will be raised.
dto="title,artist,genre,playtime"
"""
song = Song("", "", "", "").from_string(dto)
if not self._validator.validate(song):
raise ValueError("Invalid song details")
self._repository.add(song)
def mod_song(self, dto):
"""
Convert dto to song and after successful validation modify the playtime and genre of the song with
artist-title combination found in dto.
If there isn't a song with this combination ValueError will be raised.
dto="title,artist,genre,playtime"
"""
song = Song("", "", "", "").from_string(dto)
if not self._validator.validate(song):
raise ValueError("Invalid song details")
self._repository.mod(song)
def mod(self, entity):
"""
Modify an existing entity.
If the artist-title combination of entity is not found ValueError will be raised.
"""
found = False
with open(self._filename, "r") as file:
with open("temp.txt", "w") as temp_file:
for line in file:
target = song = Song("", "", "",
"").from_string(line.strip())
if song.get_artist() == entity.get_artist() and \
song.get_title() == entity.get_title():
found, target = True, entity
temp_file.write("{}\n".format(target.to_string()))
remove(self._filename)
rename("temp.txt", self._filename)
if not found:
raise ValueError("Song not found")
def test_from_string():
song = Song("", "", "", "").from_string("artist,title,120,Jazz")
assert song.get_artist() == "artist"
assert song.get_title() == "title"
assert song.get_playtime() == "120"
assert song.get_genre() == "Jazz"
def test_to_string():
assert Song("title", "artist", "Rock",
"120").to_string() == "artist,title,120,Rock"
def retrive(self, album_id: int) -> Album:
cursor = self.database_connector.cursor()
query = "SELECT * FROM Albums WHERE album_id = %s"
cursor.execute(query, (album_id,))
album = Album()
(album_id, title, year, artist_id, genre_id) = cursor.fetchone()
album.album_id = album_id
album.artist_id = artist_id
album.year = year
album.genre_id = genre_id
album.title = title
query = "SELECT genre_name FROM Genres WHERE genre_id = %s"
cursor.execute(query, (album.genre_id,))
genre_name, = cursor.fetchone()
album.genre_name = genre_name
query = "SELECT artist_name FROM Artists WHERE artist_id = %s"
cursor.execute(query, (album.artist_id,))
artist_name, = cursor.fetchone()
album.artist_name = artist_name
query = "SELECT * FROM Songs WHERE album_id = %s"
cursor.execute(query, (album_id,))
songs = []
for (song_id, album_id, artist_id, title, duration) in cursor:
song = Song()
song.song_id = song_id
song.artist_id = artist_id
song.artist_name = album.artist_name
song.album_id = album.album_id
song.album_name = album.title
song.title = title
song.duration = duration
song.genre_id = album.genre_id
song.genre_name = album.genre_name
songs.append(song)
cursor.close()
album.songs = songs
return album