Fetch Playlists from channels

[fabi321]

Fixes #174

It is still flawed. i.e. it doesn't support endless scrolling.
Furthermore I am not sure if ChannelSearch should be renamed to
ChannelVideoSearch, to be a bit more precise.

[mytja]

Hello, and thanks for your contribution, but this is really not an optimal solution.
First things first, that's not what he's asking for in #174 . He wants to retrieve all playlists (correct me if I'm wrong). I wanted to use Playlist or Channel class for that, as it already contains pretty good parser for playlists.

Your implementation is simply put, too complex. It contains too many classes, for example:

1. Why do we even use this? We don't need 2 classes to do a job, that one could. https://github.com/alexmercerind/youtube-search-python/pull/177/files#diff-e6569ebd018d9d9636c3eee438c36de8d9ee42102b6af978ded4a893400b7ee3R139
2. This sync hard-coding here is far from optimal (for async users)
3. Why do we need another RequestCore? We already have one that's working great. All of this parsing is not intended for RequestCore, but for your core class (eg. ChannelPlaylistSearchCore) - https://github.com/alexmercerind/youtube-search-python/pull/177/files#diff-e6569ebd018d9d9636c3eee438c36de8d9ee42102b6af978ded4a893400b7ee3R11

So that your PR doesn't go to waste, I'm going to build on top of your PR and afterwards merge it. (as far as I know, you need to enable "Allow maintainers to update code" or something similar on your PR, but I think it should be by default enabled)

[fabi321]

About using the Playlist Class: AFAIK it's about getting all playlists, and not their content. The latter can be done later. and about using Channel: I see no code for handling playlists there. And about fetching all playlists: that was my goal, although I just spotted a bug, that prevents this.

[fabi321]

It's just, that playlists are organized in shelves, which don't provide all playlists, but only some as a preview, that's why I parsed each shelf (that's a naming error, it should be called something like SingleShelfPlaylistSearch) separately. I do agree that the sync hardcoding is bad.

[mytja]

This should be great. Tell me what you think.

[fabi321]

I don't see any bugs anymore, so feel free to merge it.

[fabi321]

The current implementation only works for normal channels. "* - Topic" channels don't work.
In example the Beatles: The current implementation only returns all playlists that are visible in Created Playlists here. It neither returns what pops up when actually clicking on Created Playlists, nor what is in Albums & Singles

[fabi321]

Maybe this could be moved into another PR, to allow the navigation by shelves. I could live with that

[mytja]

lastEdited is definitely in response, but some playlists don't have it for some reason. Have a look at NCS. You can see some playlists have last date of editing (under playlist thumbnail in webapp), while some don't (for some reason).

About - Topic playlists. Most of these playlists are for music (not all, but most). These - Topic channels were created by YouTube internally for YouTube Music. This library supports only YouTube, but if you want YouTube Music, check it out here. You see, if I go to gaming - Topic channel, let's say Among Us (this was the first one in Gaming section), you can see there are no playlists whatsoever. These channels are not usual channels and should not be treated the same way. For retrieving albums, I recommend ytmusicapi. You can see channel names are same on YouTube, where channel name is - Topic, and on YouTube Music, where channel name is artist's name.

After all, I think this PR is ready for merging.