Creating a playlist manager in Python using a linked list provides a dynamic, flexible approach to handling music playlists. Through this project, we’ll explore how to use linked lists in Python to add, delete, and rearrange songs, allowing for efficient playlist manipulation. With linked lists, songs can be inserted at any position or removed quickly, without shifting elements, making it ideal for dynamic collections.
This project also uses various Python modules to enhance functionality:
import time
#The time module in Python provides functions to work with time-related tasks, like getting the current time, measuring execution time, and implementing delays.
import random
#By using this import random module which has methods like ,rand,randn(4,4),randint(1,100)
import csv
#By using this file we are goint to import csv file through this module we can read a file and write a data to a file.
# song object
# id, name and duration information is contained..
class Song:
def _init_(self, song_id, song_name, song_length):
self.song_id = song_id
self.song_name = song_name
self.song_length = song_length
def _str_(self):
return str({‘song_id’:self.song_id,
‘song_name’:self.song_name,
‘song_length’:self.song_length})
class ListNode:
def _init_(self, song:Song):
self.song = song
self.next = None
def _str_(self):
return str(self.song)
# Few other operation such as
# b. sorting a linkedlist based on song
# a. deletion of song,
# c. randomly picking a song for playing
class LinkedList:
def _init_(self):
self.head_node = None
self.count = 0
# Traversing the linked lists
def traversal(self):
if self.head_node is None:
return
temp_node = self.head_node
while(temp_node != None):
print(temp_node.song)
time.sleep(2)
temp_node = temp_node.next
time.sleep(2)
return
# inserting(node)at the beginning
def insert_at_start(self, node):
if self.head_node is None:
self.head_node = node
self.count = self.count + 1
return True
node.next = self.head_node
self.head_node = node
return True
# inserting(node) after a particular song
def insert_after(self, song_name, node):
temp_node = self.head_node
while(temp_node.song.song_name!=song_name):
temp_node = temp_node.next
# if song is not found
if temp_node is None:
return False
# if song is found
else:
if temp_node.next == None:
temp_node.next = node
else:
node.next = temp_node.next
temp_node.next = node
return True
def insert_before(self, song_name, node):
temp_node = self.head_node
prev_node = None
# Checking the song until we find
while(temp_node.song.song_name!=song_name):
prev_node = temp_node
temp_node = temp_node.next
# if song is not found
if temp_node == None:
return False
# if list contains only one song
if prev_node == None:
node.next = self.head_node
self.head_node = node
return True
# updating the linked list
prev_node.next = node
node.next = temp_node
return True
# Deleting (song)
def delete_song(self, song_name):
# identify the song needed to be deleted.
# Once the song is found set it in temp variable an/d update the references
curr = self.head_node
if curr.song.song_name==song_name: #delete head node
self.head_node = curr.next
del(curr)
return
while curr!=None:
if curr.next.song.song_name==song_name:
break
curr= curr.next
if curr==None :
raise Exception(“mentioned song of Model not available, cannot delete”)
temp = curr.next
curr.next = curr.next.next
del(temp)
return curr
def sort_list(self):
#The entire list will be updated according to the song.
#Note that sorting should be based specifically on the song_name.
#You can use the built-in
for i in range(0,9):
print(Song)\
#new_list=sorted(playlist_linked_list, key=lambda x: x.song_name, reverse=True)
#return new_list
def shuffle_song(self)
pass
class PlayList:
def _init_(self, id, playlist_name, linked_list:LinkedList):
self.playlist_id = id
self.playlist_name = playlist_name
self.playlist_linked_list = linked_list
def get_playlist(self):
return self.playlist_linked_list
def get_playlist_name(self):
return self.playlist_name
def get_playlist_id(self):
return self.playlist_id
class MusicPlayer:
def _init_(self):
self.playlists = list()
def add_playlist(self, new_playlist:PlayList):
self.playlists.append(new_playlist)
def play_playlist(self, playlist_name):
for playlist in self.playlists:
if playlist.get_playlist_name() == playlist_name:
playlist.get_playlist().traversal()
else:
print(‘No such playlist exists ‘)
def delete_song_from_playlist(self, playlist_name, song_name):
playlist = self.search_playlist_by_name(playlist_name)
if playlist is None:
print(“No such playlist exists “)
return
playlist.get_playlist().delete_song(song_name)
return
def sort_playlist(self, playlist_name):
playlist = self.search_playlist_by_name(playlist_name)
if playlist is None:
print(“No such playlist exists”)
return
playlist.get_playlist().sort_list()
return
def play_shuffled_song(self, playlist_name):
playlist = self.search_playlist_by_name(playlist_name)
if playlist is None:
print(“No such plalistr.”)
return
print(playlist.get_playlist().shuffle_song())
return
def list_all_playlists(self):
for playlist in self.playlists:
print(playlist.playlist_name)
def search_playlist_by_name(self, name):
for playlist in self.playlists:
if playlist.playlist_name == name:
return playlist
return None
def delete_playlist(self, name):
for playlist in self.playlists:
if playlist.playlist_name == name:
del playlist
return True
return False
def create_linked_list():
with open(‘C:\\pro1\\app_data.csv’, newline=”) as csvfile:
reader = csv.DictReader(csvfile)
linked_list = LinkedList()
for row in reader:
song = Song(row[‘Song ID’], row[‘Song Name’], row[‘Song Length’])
listnode = ListNode(song)
linked_list.insert_at_start(listnode)
return linked_list
if _name_ == “_main_”:
musicplayer = MusicPlayer()
musicPlayer1 = MusicPlayer()
linked_list = create_linked_list()
playlist = PlayList(1, ‘Songs’, linked_list)
print(“\nAdding playlist \n”)
musicplayer.add_playlist(playlist)
print(f’Playing all songs in the playlist \n’)
musicplayer.play_playlist(‘Songs’)
print(f’\nDeleting the Song with name : Lotus\n’)
musicplayer.delete_song_from_playlist(‘Songs’, ‘Lotus’)
musicplayer.play_playlist(‘Songs’)
print(‘\nPlaying all songs after sorted based on names \n’)
musicplayer.sort_playlist(‘Songs’)
musicplayer.play_playlist(‘Songs’)
print(‘\nPlaying shuffled song \n’)
musicplayer.play_shuffled_song(‘Songs’)