Repository: yt-dlp
Issue: CSV format support + missing field values in `%( )l` comma separated list of `key:value` pairs
Labels: enhancement,triage

### DO NOT REMOVE OR SKIP THE ISSUE TEMPLATE

- [X] I understand that I will be **blocked** if I *intentionally* remove or skip any mandatory\* field

### Checklist

- [X] I'm asking a question and **not** reporting a bug or requesting a feature
- [X] I've looked through the [README](https://github.com/yt-dlp/yt-dlp#readme)
- [X] I've verified that I'm running yt-dlp version **2023.03.04** ([update instructions](https://github.com/yt-dlp/yt-dlp#update)) or later (specify commit)
- [X] I've searched [known issues](https://github.com/yt-dlp/yt-dlp/issues/3766) and the [bugtracker](https://github.com/yt-dlp/yt-dlp/issues?q=) for similar questions **including closed ones**. DO NOT post duplicates
- [X] I've read the [guidelines for opening an issue](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#opening-an-issue)

### Please make sure the question is worded well enough to be understood

I can output `requested_format` as json `key:value` pairs but when I try to output it as comma-separated-values with `%(requested_formats)l` or `%(requested_formats)#l` I am missing the values (see log below). How can I get the values? I'd like to output csv files.

### Provide verbose output that clearly demonstrates the problem

- [X] Run **your** yt-dlp command with **-vU** flag added (`yt-dlp -vU <your command line>`)
- [X] If using API, add `'verbose': True` to `YoutubeDL` params instead
- [X] Copy the WHOLE output (starting with `[debug] Command-line config`) and insert it below

### Complete Verbose Output

```json
yt-dlp ZYlALC1Pmv4 --skip-download --no-config --print %(requested_formats.1)#j
{
    "asr": 48000,
    "filesize": 41488798,
    "format_id": "251",
    "format_note": "medium",
    "source_preference": -1,
    "fps": null,
    "audio_channels": 2,
    "height": null,
    "quality": 3.0,
    "has_drm": false,
    "tbr": 112.176,
    "url": "https://rr3---sn-h0jeenle.googlevideo.com/videoplayback?......",
    "width": null,
    "language": null,
    "language_preference": -1,
    "preference": null,
    "ext": "webm",
    "vcodec": "none",
    "acodec": "opus",
    "dynamic_range": null,
    "container": "webm_dash",
    "downloader_options": {
        "http_chunk_size": 10485760
    },
    "protocol": "https",
    "resolution": "audio only",
    "aspect_ratio": null,
    "http_headers": {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36",
        "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
        "Accept-Language": "en-us,en;q=0.5",
        "Sec-Fetch-Mode": "navigate"
    },
    "audio_ext": "webm",
    "video_ext": "none",
    "abr": 112.176,
    "format": "251 - audio only (medium)"
}
```

```sh
yt-dlp ZYlALC1Pmv4 --skip-download --no-config --print %(requested_formats.1)#l
asr
filesize
format_id
format_note
source_preference
fps
audio_channels
height
quality
has_drm
tbr
url
width
language
language_preference
preference
ext
vcodec
acodec
dynamic_range
container
downloader_options
protocol
resolution
aspect_ratio
http_headers
audio_ext
video_ext
abr
format
```