44 — Playlist: a random music player

A music player walks a list of songs — load it from JSON, mix it with the random helper, and loop a menu until you quit.

#Steps

1. Save five songs in songs.json — a JSON list of dicts with title and artist:

   [
     {"title": "Hello", "artist": "Adele"},
     {"title": "Dynamite", "artist": "BTS"},
     {"title": "Love Dive", "artist": "IVE"},
     {"title": "Life Goes On", "artist": "BTS"},
     {"title": "Butter", "artist": "BTS"}
   ]
   

   copyrun it →

2. Load the list with json_load, mix it with shuffle, and jump around with random_pick. Save the whole player as playlist.nme:

   # playlist.nme — a random music player.
   # Run: nme r playlist
   
   use random latest
   use file latest
   
   songs = json_load("songs.json")
   shuffle(songs)
   
   current = 0
   
   show f"Playlist loaded: {len(songs)} songs"
   
   while True:
       show ""
       show "Commands: next, prev, list, quit"
       ask command, "? "
       if command == "next":
           current = current + 1
           if current >= len(songs):
               current = 0
           song = songs[current]
           show f"Now playing: {song['title']} by {song['artist']}"
       elif command == "prev":
           current = current - 1
           if current < 0:
               current = len(songs) - 1
           song = songs[current]
           show f"Now playing: {song['title']} by {song['artist']}"
       elif command == "list":
           show f"Playlist ({len(songs)} songs):"
           for i in range(len(songs)):
               mark = "> " if i == current else "  "
               show f"{mark}{i + 1}. {songs[i]['title']} by {songs[i]['artist']}"
       elif command == "quit":
           show "Bye!"
           break
   

   copyrun it →

3. Run it and feed the commands through a pipe:

   printf 'next\nnext\nlist\nquit\n' | nme r playlist
   

   copy

   Playlist loaded: 5 songs
   
   Commands: next, prev, list, quit
   ? Now playing: Butter by BTS
   
   Commands: next, prev, list, quit
   ? Now playing: Hello by Adele
   
   Commands: next, prev, list, quit
   ? Playlist (5 songs):
     1. Life Goes On by BTS
     2. Butter by BTS
   > 3. Hello by Adele
     4. Love Dive by IVE
     5. Dynamite by BTS
   
   Commands: next, prev, list, quit
   ? Bye!
   

   copy

   next wraps past the end and prev wraps to the last song; shuffle mixes the order.

#Try it yourself

Add a count command that asks for an artist and prints how many of their songs are in the playlist — loop over songs and grow a counter.

#What you learned

• use random latest and use file latest load both helpers together.
• json_load("songs.json") reads the song list; shuffle(songs) mixes it; random_pick(songs) jumps around.
• songs[current] reads one song; wrapping the index loops the playlist.
• A while True menu with ask, show, and break drives the player.