How can youtube-dl download videos that require user authentication and 2FA?

Question

When I try to download on of my private videos I get the following:

youtube-dl https://youtu.be/Q-xxxx-xxxx
[youtube] Q-xxxx-xxxx: Downloading webpage
[youtube] Q-xxxx-xxxx: Downloading video info webpage
WARNING: Unable to extract video title
ERROR: This video is unavailable.

When I try to use username and password it fails on my 2FA.

youtube-dl --username=[e-mail]  https://youtu.be/Q-xxxx-xxxx
Type account password and press [Return]: 
[youtube] Downloading login page
[youtube] Looking up account info
[youtube] Logging in
Type 2-step verification code and press [Return]: 
[youtube] Submitting TFA code
WARNING: Unable to submit TFA code: HTTP Error 400: Bad Request
[youtube] Q-xxxx-xxxx: Downloading webpage
[youtube] Q-xxxx-xxxx: Downloading video info webpage
WARNING: Unable to extract video title
ERROR: This video is unavailable.

If I try to use --cookies exported with EditThisCookie in Chrome then it also fails. I exported by going to the video in Chrome and copying the cookies into a file.

youtube-dl --cookies=cookies.txt  https://youtu.be/Q-xxxx-xxxx
Traceback (most recent call last):
  File "/usr/bin/youtube-dl", line 11, in <module>
    load_entry_point('youtube-dl==2018.6.14', 'console_scripts', 'youtube-dl')()
  File "/usr/lib/python3.6/site-packages/youtube_dl/__init__.py", line 472, in main
    _real_main(argv)
  File "/usr/lib/python3.6/site-packages/youtube_dl/__init__.py", line 439, in _real_main
    with YoutubeDL(ydl_opts) as ydl:
  File "/usr/lib/python3.6/site-packages/youtube_dl/YoutubeDL.py", line 414, in __init__
    self._setup_opener()
  File "/usr/lib/python3.6/site-packages/youtube_dl/YoutubeDL.py", line 2303, in _setup_opener
    self.cookiejar.load()
  File "/usr/lib/python3.6/http/cookiejar.py", line 1784, in load
    self._really_load(f, filename, ignore_discard, ignore_expires)
  File "/usr/lib/python3.6/http/cookiejar.py", line 2007, in _really_load
    filename)
http.cookiejar.LoadError: 'cookies.txt' does not look like a Netscape format cookies fil

How can I download my private video with youtube-dl?

EDIT:

I also tried an app password but for some reason this also failed for me:

youtube-dl --username=[e-mail] --password=xxxxxxxxx youtu.be/Q-xxxxxxxx
[youtube] Downloading login page
[youtube] Looking up account info
[youtube] Logging in
WARNING: Unable to login: Invalid password
[youtube] Q-xxxxxx: Downloading webpage
[youtube] Q-xxxxxx: Downloading video info webpage
WARNING: Unable to extract video title
ERROR: This video is unavailable.

Answer 1

I was able to download private videos by using the --cookies route. I had to first format the cookies to Netscape format, which is an option in EditThisCookie. Remember you'll not only need the cookies for https://youtube.com but also for https://accounts.google.com. You'll have to do this manually with EditThisCookie Chrome plugin.

I then needed to fix the format of the cookies generated with EditThisCookie with curl. Something like: curl -b oldcookiefile.txt --cookie-jar newcookiefile.txt 'https://youtube.com'.

The --cookies flag can then be used with youtube-dl to download private videos.

I also created a blog post describing what I learned in more detail.