YouTube Downloader and Trimmer

.zshrc

# Add this to your `~/.bash_profile` or `~/.zshrc` file,
# so that running the Python script in the terminal is more convenient.

# Command: yvt URL START_TIME END_TIME
# Sample: yvt 'https://www.youtube.com/watch?v=RjxKVAOZCQY' 9:41 10:58
yt_video_trimmer() {
    python <PATH TO>/yt-video-trimmer.py $1 $2 $3
}
alias yvt=yt_video_trimmer

yt-video-trimmer.py

"""
Needs PyTube (downloader) and MoviePy (trimmer) libraries.
$ pip install pytube
$ pip install moviepy
"""
import os
from sys import argv

from moviepy.editor import VideoFileClip
from pytube import YouTube


URL = argv[1]

start_time_components = argv[2].split(':')
start_time_minutes = int(start_time_components[0]) * 60  # Convert to seconds
start_time_seconds = float(start_time_components[1])
START_TIME = start_time_minutes + start_time_seconds

end_time_components = argv[3].split(':')
end_time_minutes = int(end_time_components[0]) * 60  # Convert to seconds
end_time_seconds = float(end_time_components[1])
END_TIME = end_time_minutes + end_time_seconds

FILE_NAME_DOWNLOADED_VIDEO = 'downloaded_video.mp4'
FILE_NAME_TRIMMED_VIDEO = 'trimmed_video.mp4'


print('\nDownloading video...')

# API: https://pytube.io/en/latest/api.html
yt_video = YouTube(URL)

# Downloads the `progressive=True` variant which bundles both the video and audio.
# `progressive=False` has better resolution but requires merging video and audio using FFMPEG.
yt_video.streams.get_highest_resolution().download(filename=FILE_NAME_DOWNLOADED_VIDEO)


print('\nTrimming video...')

# API: https://zulko.github.io/moviepy/ref/ref.html
# https://zulko.github.io/moviepy/ref/Clip.html#moviepy.Clip.Clip.subclip
clip = VideoFileClip(FILE_NAME_DOWNLOADED_VIDEO)
trimmed_video = clip.subclip(START_TIME, END_TIME)
trimmed_video.write_videofile(FILE_NAME_TRIMMED_VIDEO)


print('\nRemoving downloaded video...')

os.remove(FILE_NAME_DOWNLOADED_VIDEO)