This prints the text from 1% to 100%, all on the same line since it uses stdout.write rather than print. However, before printing each percentage it first prints \u001b[1000D, which means "move cursor left by 1000 characters). This should move it all the way to the left of the screen, thus letting the new percentage that gets printed over-write the old one. Hence we see the loading percentage seamlessly changing from 1% to 100% before the function returns:
Европеец описал впечатления от дворца в России фразой «рот открылся и не закрывался»17:34，推荐阅读wps获取更多信息
Нанесен удар по портовому терминалу Одессы с ракетами и иностранными военными02:51。关于这个话题，手游提供了深入分析
dev.write(1, b'\x01\x94\x01\x00\x01\x00\x10\x00\x04\x00')