[Youtube] flat-playlist extractor correction for playlist results and partial added duration

[Crypto90]

Checklist

• I'm reporting a feature request
• I've verified that I'm running youtube-dl version 2020.06.16.1
• I've searched the bugtracker for similar feature requests including closed ones

Description

WRITE DESCRIPTION HERE

In the uploaded youtube.py.txt file I have made some changes for the youtube.py extractor to add the new feature to get correct results when searching youtube playlists.
The changed code checks if the /wach?v= url also contains list=, if so, also the playlist id gets extracted.
The printed result will also be checked for the video id length (11 = video id, larger than 11 = playlist id)

RESULTS searching for playlists:

python youtube-dl -4 --no-warnings --no-check-certificate "ytsearch10:nightcore,playlist" --dump-json --playlist-start 1 --playlist-end 10 --flat-playlist
{"url": "https://www.youtube.com/playlist?list=PL0wqt_um4x0bsdViTJBmnl6KGMoSqxfZy", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PL0wqt_um4x0bsdViTJBmnl6KGMoSqxfZy", "title": "Most Viewed Nightcore"}
{"url": "https://www.youtube.com/playlist?list=PLckeMyCaCCIN_JU1V4oADW50DlGOREoLj", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PLckeMyCaCCIN_JU1V4oADW50DlGOREoLj", "title": "Ultimatum [Nightcore playlist]"}
{"url": "https://www.youtube.com/playlist?list=PLyTi20i8cwsPyiwvjei-K6F04Rzm0uRpT", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PLyTi20i8cwsPyiwvjei-K6F04Rzm0uRpT", "title": "Old School Nightcore"}
{"url": "https://www.youtube.com/playlist?list=PLMk3t51Sma9Ez2tjSzks3N06cwckoz2-m", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PLMk3t51Sma9Ez2tjSzks3N06cwckoz2-m", "title": "NightCore Emo"}
{"url": "https://www.youtube.com/playlist?list=PLT5Nlf1NmV4Mqfha4j1YuCTk0GCL20bdN", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PLT5Nlf1NmV4Mqfha4j1YuCTk0GCL20bdN", "title": "BoxBox Nightcore COMPLETE"}
{"url": "https://www.youtube.com/playlist?list=PLOTApxgUwuOKLxLhKAs8IVY7gPO7jBzD2", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PLOTApxgUwuOKLxLhKAs8IVY7gPO7jBzD2", "title": "Nightcore - Gacha Songs"}
{"url": "https://www.youtube.com/playlist?list=PL_2-M0cHcLO4PYOoiyq0PxOeHqGlhlnmQ", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PL_2-M0cHcLO4PYOoiyq0PxOeHqGlhlnmQ", "title": "The Ultimate Nightcore Playlist"}
{"url": "https://www.youtube.com/playlist?list=PLT2qINU1sbUh0ECl94rEWddz9dLA10t6H", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PLT2qINU1sbUh0ECl94rEWddz9dLA10t6H", "title": "Nightcore Playlist"}
{"url": "https://www.youtube.com/playlist?list=PLM6aAK5yk-8KWSSW8zJCBkNCP_Kvom6S5", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PLM6aAK5yk-8KWSSW8zJCBkNCP_Kvom6S5", "title": "Sexual Nightcore Songs"}
{"url": "https://www.youtube.com/playlist?list=PLNNA4xoj8rtiyGCKKW-ZJAgE07puDN9wb", "_type": "url", "ie_key": "YoutubePlaylist", "id": "PLNNA4xoj8rtiyGCKKW-ZJAgE07puDN9wb", "title": "Upbeat Nightcore"}

RESULTS searching for single videos:

python youtube-dl -4 --no-warnings --no-check-certificate "ytsearch10:nightcore,video" --dump-json --playlist-start 1 --playlist-end 10 --flat-playlist
{"url": "fSlOHZXhcMk", "_type": "url", "ie_key": "Youtube", "id": "fSlOHZXhcMk", "title": "Nightcore - Dracula - (Lyrics)"}
{"url": "0NSCkfyA6uY", "_type": "url", "ie_key": "Youtube", "id": "0NSCkfyA6uY", "title": "Nightcore - Stick Together"}
{"url": "nuTsXUYUavw", "_type": "url", "ie_key": "Youtube", "id": "nuTsXUYUavw", "title": "Nightcore - What You Made Me - (Lyrics)"}
{"url": "E3FfwK81OsU", "_type": "url", "ie_key": "Youtube", "id": "E3FfwK81OsU", "title": "Nightcore - Savage Love - (Lyrics)"}
{"url": "hjGZLnja1o8", "_type": "url", "ie_key": "Youtube", "id": "hjGZLnja1o8", "title": "Nightcore - Rockefeller Street"}
{"url": "9xG5aPvrS-k", "_type": "url", "ie_key": "Youtube", "id": "9xG5aPvrS-k", "title": "Nightcore - No Friends (Lyrics)"}
{"url": "cvaIgq5j2Q8", "_type": "url", "ie_key": "Youtube", "id": "cvaIgq5j2Q8", "title": "Nightcore - Angel With A Shotgun"}
{"url": "Zm1vKR2hNyc", "_type": "url", "ie_key": "Youtube", "id": "Zm1vKR2hNyc", "title": "Nightcore - Odds Are - (Lyrics)"}
{"url": "z6lJlIp9Y50", "_type": "url", "ie_key": "Youtube", "id": "z6lJlIp9Y50", "title": "Nightcore - Tick Tick Tick - (Lyrics)"}
{"url": "cyW2ajAVyfA", "_type": "url", "ie_key": "Youtube", "id": "cyW2ajAVyfA", "title": "Nightcore - Take A Hint"}

I have also changed the video regex to fetch the video durations, which already works, but at line 327

if len(video_id) == 11:
                #youtube video id found
                yield self.url_result(video_id, 'Youtube', video_id, video_title)

the self.url_result(...) function errors if I change it to:

if len(video_id) == 11:
                #youtube video id found
                yield self.url_result(video_id, 'Youtube', video_id, video_title, video_duration)

That it expects 4 arguments and not 5. I looked at the code where the self.url_result(...) function is defined but I could not find it. Maybe someone can help out here for this last step.

Other topic relations:
#25720
#16627
#25652

youtube.py.txt

[Crypto90]

I also want to fetch the videos counter of each youtube playlist result, but I did not get the regex working for that.
The videos count information is there. But to make it simple, I will split the playlists video counter changes with this request.
The html code for each playlist videos counter looks like this:

<span class="formatted-video-count-label"><b>352</b> videos</span>

[dstftw]

File a PR.

[Crypto90]

@dstftw I tried, I never have done a pull request here. If I click the "New pull request" button, I can only compare branches.
Or is it a simple commit which get transformed to a pull request?

[dstftw]

Read developer instructions.