youtube_video_id.py

# Source: https://stackoverflow.com/a/7936523
from urllib.parse import urlparse, parse_qs


def extract_video_id(value):
    """
    Examples:
    - http://youtu.be/SA2iWivDJiE
    - http://www.youtube.com/watch?v=_oPAwA_Udwc&feature=feedu
    - http://www.youtube.com/embed/SA2iWivDJiE
    - http://www.youtube.com/v/SA2iWivDJiE?version=3&hl=en_US
    """
    query = urlparse(value)
    if query.hostname == "youtu.be":
        return query.path[1:]
    if query.hostname in ("www.youtube.com", "youtube.com"):
        if query.path == "/watch":
            p = parse_qs(query.query)
            return p["v"][0]
        if query.path[:7] == "/embed/":
            return query.path.split("/")[2]
        if query.path[:3] == "/v/":
            return query.path.split("/")[2]
    # fail?
    return None