Simple downloader from youtube with pytube.
It has the following functions:
- mp4_2_mp3 to convert from mp4 files to mp3 files
- yt_downloader_audio to download a video from youtube and get only the audio (useful for music videos)
- yt_downloader_video to download a video from youtube
- yt_playlist_downloader_audio to get the audio of all the videos of a playlist
- yt_playlist_downloader_video to get all the videos of a playlist