1#!/usr/bin/env python3
2"""
3This script receives a YouTube URL on stdin, and removes the `list`
4query parameter.
5
6I use this in conjunction with `furl` and `youtube-dl`.  Sometimes
7I want to download a single video from YouTube, but youtube-dl tries
8to download an entire playlist.  This lets me grab just the first video.
9"""
10
11import sys
12import urllib.parse
13
14import pytest
15
16
17def noplaylist(url: str) -> str:
18    """
19    Remove the playlist query parameters from a URL.
20    """
21    u = urllib.parse.urlsplit(url)
22
23    query = urllib.parse.parse_qs(u.query)
24    for name in ("list", "index", "pp"):
25        try:
26            del query[name]
27        except KeyError:
28            pass
29
30    return urllib.parse.urlunsplit(
31        (
32            u.scheme,
33            u.netloc,
34            u.path,
35            urllib.parse.urlencode(query, doseq=True),
36            u.fragment,
37        )
38    )
39
40
41@pytest.mark.parametrize(
42    "original_url, url",
43    [
44        (
45            "https://www.youtube.com/watch?v=wrhDXOZoQ74&list=PL7lRfPsqWBLZ9HK6t-BBaVBgRlkLg_FNI&index=4&pp=iAQB",
46            "https://www.youtube.com/watch?v=wrhDXOZoQ74",
47        ),
48        (
49            "https://www.youtube.com/watch?v=wrhDXOZoQ74",
50            "https://www.youtube.com/watch?v=wrhDXOZoQ74",
51        ),
52    ],
53)
54def test_noplaylist(original_url: str, url: str) -> None:
55    """
56    Tests for `noplaylist()`.
57    """
58    assert noplaylist(original_url) == url
59
60
61if __name__ == "__main__":
62    url = sys.stdin.read()
63    url = noplaylist(url)
64    sys.stdout.write(url)