Program 1
# Music Play list based on Doubly Linked List
class Song: # Node of doubly linked list
def __init__(self, title):
self.prev = None
self.title = title
self.next = None
class MusicPlaylist:
def __init__(self):
self.head = None
self.tail = None
self.current = None
def add_song(self, title):
new_song = Song(title) # Create Node
if self.head==None:
self.head = self.tail = self.current = new_song
else:
self.tail.next = new_song
new_song.prev = self.tail
self.tail = new_song
print(f"Added: {title}")
def delete_current_song(self):
if not self.current:
print("No song to delete.")
return
print(f"Deleting: {self.current.title}")
if self.current.prev!=None:
self.current.prev.next = self.current.next
else:
self.head = self.current.next
if self.current.next!=None:
self.current.next.prev = self.current.prev
else:
self.tail = self.current.prev
temp = self.current
self.current = self.current.next if self.current.next else self.current.prev
del temp
if not self.current:
print("Playlist is now empty.")
else:
print(f"Now playing: {self.current.title}")
def next_song(self):
if self.head==None:
print("\nPlaylist is empty...")
else:
if self.current and self.current.next:
self.current = self.current.next
print(f"Now playing: {self.current.title}")
else:
print("You're at the end of the playlist.")
def prev_song(self):
if self.head==None:
print("\nPlaylist is empty...")
else:
if self.current and self.current.prev:
self.current = self.current.prev
print(f"Now playing: {self.current.title}")
else:
print("You're at the start of the playlist.")
# Show Play List Function
def display_playlist(self):
if self.head==None:
print("\nPlaylist is empty...")
return
print("\nPlaylist:")
temp = self.head
while temp:
if temp == self.current:
print(f"--> {temp.title} [CURRENT SONG]")
else:
print(f" {temp.title}")
temp = temp.next
print()
def clear_playlist(self):
while self.head:
temp = self.head
self.head = self.head.next
del temp
self.tail = self.current = None
def main():
playlist = MusicPlaylist()
while True:
print("\n---------------------Music Playlist--------------------")
print("1. Add Song")
print("2. Delete Current Song")
print("3. Next Song")
print("4. Previous Song")
print("5. Show Playlist")
print("6. Exit")
print("-----------------------------------------------------------")
choice = input("Enter your choice: ")
if choice == '1':
title = input("Enter song title: ")
playlist.add_song(title)
elif choice == '2':
playlist.delete_current_song()
elif choice == '3':
playlist.next_song()
elif choice == '4':
playlist.prev_song()
elif choice == '5':
playlist.display_playlist()
elif choice == '6':
playlist.clear_playlist()
print("Exiting playlist.")
break
else:
print("Invalid choice.")
if __name__ == "__main__":
main()
