Download the first song from youtube by searching for "artist - song"

download.py

#!/usr/bin/env python3

import fileinput
import os
import random
import re
import string
import subprocess

def rand_str(k=12):
	cs = string.ascii_uppercase + string.digits
	return ''.join(random.choice(cs) for _ in range(k))

def run(args, quiet):
	fds = {}
	if quiet:
		fds = {'stdout':subprocess.DEVNULL, 'stderr':subprocess.DEVNULL}
	return subprocess.run(args, **fds)
	
def run_youtube_dl(output_format, arg, quiet):
	args = ['youtube-dl', '-o', output_format, arg]
	if run(args, quiet).returncode != 0:
		raise Exception("youtube-dl error")

def run_ffmpeg(filename, output, quiet, **kw):
	args = ['ffmpeg', '-loglevel', 'error', '-y', '-i', filename, '-acodec', 'copy']
	for k in kw:
		v = kw[k]
		if v is not None:
			args.append('-metadata')
			args.append('{key}={value}'.format(key=k, value=v))
	args.append(output)
	
	if run(args, quiet).returncode != 0:
		raise Exception("ffmpeg error")

def download(artist, title, dl_link=None, quiet=True, delete=True, **kwargs):
	prefix_len = 12
	prefix = rand_str(prefix_len)
	output_format = prefix + '%(title)s+++++%(id)s.%(ext)s'
	arg = dl_link or 'ytsearch1:{artist} - {title}'.format(artist=artist, title=title)
	run_youtube_dl(output_format, arg, quiet)
	
	tmp_file = [p for p in os.listdir('.') if p.startswith(prefix)][0]
	tmp = tmp_file[prefix_len:tmp_file.rfind('.')]  # remove prefix and extension
	yt_title, video_id = tmp.split('+++++')
	
	ys = re.findall(r'\b\d{4}\b', yt_title)
	year = ys[0] if len(ys)==1 else None
	
	out_file = title + '.mp3'
	run_ffmpeg(
		tmp_file, out_file, quiet,
		title=title, artist=artist,
		year=year, date=year,
		comments='yt:{id}'.format(id=video_id),
		**kwargs
	)
	
	if delete:
		os.unlink(tmp_file)


if __name__ == '__main__':
	for line in fileinput.input():
		line = line.strip()
		if not line:
			continue
		args = line.split()
		if args[-1].startswith('http'):
			dl_link = args.pop()
		else:
			dl_link = None
		
		sep = args.index('-')
		artist = ' '.join(args[:sep])
		title = ' '.join(args[sep+1:])
		
		print('Downloading: %s - %s' % (artist, title))
		#download(artist, title, dl_link=dl_link, genre='Cajke')

youtube-dl.config

--ignore-errors
--mark-watched

--output '%(title)s.%(ext)s'
--restrict-filenames  # ascii only
--no-mtime

--user-agent 'Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)'

--extract-audio
--audio-format mp3
--format bestaudio

--embed-thumbnail

--prefer-ffmpeg
--hls-prefer-ffmpeg