Downloads 1080 video and 128Kbps audio form youtube separately and combine them afterwords.

pytube_hd_dl

from pytube import YouTube
import sys
import time
# from ffmpeg import _ffmpeg as ffmpeg
import ffmpeg

class YoutubeDL:
    _video = None
    _audio = None

    def progress_func(self, stream, chunk, file_handle, bytes_remaining):
        bar_length = 20
        percent = (1 - bytes_remaining / self._video.filesize)
        hashes = '=' * int(round(percent * bar_length))
        spaces = ' ' * (bar_length - len(hashes))
        progress = round(percent * 100, 3)
        sys.stdout.write('\rProgress: [{0}] {1}%'.format(hashes + spaces, progress))
        sys.stdout.flush()

    def cli_progress_test(self, end_val, bar_length=20):
        for i in range(0, end_val):
            percent = float(i) / end_val
            hashes = '#' * int(round(percent * bar_length))
            spaces = ' ' * (bar_length - len(hashes))
            sys.stdout.write("\rPercent: [{0}] {1}%".format(hashes + spaces, int(round(percent * 100))))
            sys.stdout.flush()
            time.sleep(1)

    def __init__(self):
        try:
            yt = YouTube('https://www.youtube.com/watch?v=C9LPQmkao8c', on_progress_callback=self.progress_func)
            streams = yt.streams
            self._video = streams.filter(adaptive=True, file_extension='mp4', type='video').first()
            self._audio = streams.filter(adaptive=True, file_extension='mp4', type='audio').first()

            # print('downloading video:', yt.title+"_video")
            # self._video.download()
            # print('\nTask Completed!')

            # print('downloading audio:', yt.title)
            # self._audio.download(filename=yt.title + "_audio")
            # print('\nTask Completed!')

            # mixing audio and video file
            video_input = ffmpeg.input('Of Monsters and Men - Wild Roses.mp4')
            audio_input = ffmpeg.input('Of Monsters and Men - Wild Roses_audio.mp4')
            ffmpeg.output(audio_input, video_input, 'out.mp4').run()

            # ffmpeg.output(self._audio, self._video, 'out.mp4').run()
        except Exception as ex:
            print(ex)  # to handle exception

YoutubeDL()