Not a directory but have contents

So I use Compute Engine VM in Google Cloud to download youtube videos. I use Youtube-dl to download it. I follow the documentation in here: https://github.com/ytdl-org/youtube-dl/blob/master/README.md#how-do-i-update-youtube-dl After I install youtube-dl and try to run it, I found an error:

File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1794, in _real_extract
    'uploader_id': self._search_regex(r'/(?:channel|user)/([^/?&#]+)', owner_profile_url, 'uploader id') if owner_profile_url else None,

A simple error, and I know how to fix this. I just need to head into

/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py

and look at line 1794 The thing is, when I try to nano the address, it's not a directory. It makes me confuse. It literally said that I have error in that directory but now that's not a directory. I use this to install youtube-dl:

sudo curl -L https://yt-dl.org/downloads/latest/youtube-dl  -o /usr/local/bin/youtube-dl
sudo chmod a+rx /usr/local/bin/youtube-dl

I try to add write acc with

chmod +w /usr/local/bin/youtube-dl

but I still can't edit it. Can anyone explain why it's not a directory when it said that it's in the error message? And how to access it? Edit: I try

-lad youtube-dl

and get:

-rwxrwxrwx 1 root root 1837828 Jul 13 07:58 youtube-dl

Also

youtube-dl

and get:

youtube-dl: a /usr/bin/env python script executable (binary data)