[Tech support] How to get filename after a download has completed (Python)

[devxpy]

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Hello,
I want to download audio files using Python (using --extract-audio) and then get the final filename after youtube-dl / ffmpeg are done with it.

Example

subprocess.run([
                'youtube-dl',
                '--extract-audio', '--restrict-filenames',
                '-o', DL_DIR.joinpath(f'{song.spotify_id}.%(ext)s'),
                song.youtube_id
            ])

output-

[youtube] mMoVvCEYMKM: Downloading webpage
[youtube] mMoVvCEYMKM: Downloading video info webpage
[youtube] mMoVvCEYMKM: Extracting video information
[download] /home/dev/Projekt/encadio/downloads/English/4gLuKrWf0Ub3nwrRB0yJk7.m4a has already been downloaded
[download] 100% of 3.27MiB
[ffmpeg] Correcting container in "/home/dev/Projekt/encadio/downloads/English/4gLuKrWf0Ub3nwrRB0yJk7.m4a"
[ffmpeg] Post-process file /home/dev/Projekt/encadio/downloads/English/4gLuKrWf0Ub3nwrRB0yJk7.m4a exists, skipping

Now how do I know what the final filename (or just the file extension) was, after the download finished?

I could also do this, as suggested by readme

with youtube_dl.YoutubeDL(ydl_opts) as ydl:                
    ydl.download(['https://www.youtube.com/watch?v=BaW_jenozKc'])

But I couldn't find the final filename in ydls attributes.

I could have my application work by just searching using song.spotify_id, but that seems a little janky?

[devxpy]

Sorry, my bad. Didn't see the full example.
It's available like this

    def my_hook(d):
        if d['status'] == 'finished':
            print(d['filename'])

    ydl_opts = {
        'format': 'bestaudio',
        'progress_hooks': [my_hook],
    }
    with youtube_dl.YoutubeDL(ydl_opts) as ydl:
        ydl.download(['https://www.youtube.com/watch?v=BaW_jenozKc'])

[Moriand]

please a complete example, I need to understand it completely

[devxpy]

Just import youtube_dl I guess..

[Moriand]

Well, well, you go there, rather I wanted to know what more options it offers, for example:
I want to download the subtitle
as after download, I convert to mp3 or other audio formats

[devxpy]

Never tried doing subtitles, will try..

If you convert to other format, d['filename'] returns the filename for converted format