---
layout: post
title: "List YouTube playlist with youtube-dl"
date: 2014-11-05 10:37:58 -0800
comments: true
categories: [youtube, video, 'web scraping']
---
Of course you are always welcome to use the [Google APIs Client Library for Python](https://developers.google.com/api-client-library/python/) to wrestle with YouTube, which is usually pretty simple. (As an added bonus, YouTube has some [nice runnable sample scripts](https://developers.google.com/youtube/v3/code_samples/) to get you started.) With the client library, listing videos in a YouTube playlist is a breeze.

However, if you don't feel like writing code yourself (I usually don't feel like writing code myself until I use something often enough and existing solutions are suboptimal), `youtube-dl` recently added the functionality to list videos in a playlist with the `--flat-playlist` option.

[According to one of the project collaborators](https://github.com/rg3/youtube-dl/issues/4003#issuecomment-60322630), currently `--flat-playlist` is only helpful with the `-j` option for dumping JSON (so I suppose this feature is subject to change). For instance, `--flat-playlist` alone would emit something like this:

```bash
> youtube-dl --flat-playlist 'https://www.youtube.com/watch?v=gdOwwI0ngqQ&list=PLPpZI8R1zUfrkDbmJMOBhEbJ9Td9vbV-F'
[youtube:playlist] Downloading playlist PLPpZI8R1zUfrkDbmJMOBhEbJ9Td9vbV-F - add --no-playlist to just download video gdOwwI0ngqQ
[youtube:playlist] PLPpZI8R1zUfrkDbmJMOBhEbJ9Td9vbV-F: Downloading webpage
[youtube:playlist] PLPpZI8R1zUfrkDbmJMOBhEbJ9Td9vbV-F: Downloading page #1
[download] Downloading playlist: Cam By apinknomfan
[youtube:playlist] playlist Cam By apinknomfan: Collected 119 video ids (downloading 119 of them)
[download] Downloading video #1 of 119
[download] Downloading video #2 of 119
[download] Downloading video #3 of 119
[download] Downloading video #4 of 119
...
```

which doesn't really make sense — it tells you that it collected 119 video ids, and no more. Once you have `-j` on, you get JSON data that you can parse with anything:

```bash
> youtube-dl -j --flat-playlist 'https://www.youtube.com/watch?v=gdOwwI0ngqQ&list=PLPpZI8R1zUfrkDbmJMOBhEbJ9Td9vbV-F'
{"url": "gdOwwI0ngqQ", "_type": "url", "ie_key": "Youtube", "id": "gdOwwI0ngqQ"}
{"url": "j9l5nchv1Z8", "_type": "url", "ie_key": "Youtube", "id": "j9l5nchv1Z8"}
{"url": "znW5ALwWNQw", "_type": "url", "ie_key": "Youtube", "id": "znW5ALwWNQw"}
{"url": "qyE7-auTIcc", "_type": "url", "ie_key": "Youtube", "id": "qyE7-auTIcc"}
...
```

The most straightforward way to parse this is to use a command line JSON parser, the best one being [jq](https://github.com/stedolan/jq):

```bash
> youtube-dl -j --flat-playlist 'https://www.youtube.com/watch?v=gdOwwI0ngqQ&list=PLPpZI8R1zUfrkDbmJMOBhEbJ9Td9vbV-F' | jq -r '.id' | sed 's_^_https://youtube.com/v/_'
https://youtube.com/v/gdOwwI0ngqQ
https://youtube.com/v/j9l5nchv1Z8
https://youtube.com/v/znW5ALwWNQw
https://youtube.com/v/qyE7-auTIcc
...
```

There you go, a list of URIs you can use. Of course you can put this in a script to save some typing:

{% gist 0245788475f963210ed9 %}

By the way, `youtube-dl` supports playlist bulk download natively. The reason I need a list of video ids or URIs, however, is that among other things, `youtube-dl` doesn't download highest resolution DASH video by default, so I have to rely on something like `youtube-dl-dash` ([link](https://github.com/zmwangx/sh/blob/master/youtube-dl-dash)) to download the best version.