Correct. Each class that handles information extraction for a different side defines a regexp to match the url against. (Note: Some of the regexps aren't hardy to the http-vs-https distinction, so you might have to remove the 's')

Awesome, thanks. Should have tried before asking. :) Searched my system drive for these .py files, but found nothing, so I figured something was missing.

All of the modules are compiled into a single file for the youtube-dl command. I've never looked into what they are using to do this, but you could poke your head into the repo to check it out.

We're simply making use of Python's ability to load a module from a zip file [0]. Therefore, the generation[1] is just zipping up all the files and prepending a shebang.

[0] http://bugs.python.org/issue1739468 [1] https://github.com/rg3/youtube-dl/blob/640743233389714dda8a3...

This:

  youtube-dl: youtube_dl/*.py youtube_dl/*/*.py
  	zip --quiet youtube-dl youtube_dl/*.py youtube_dl/*/*.py
  	zip --quiet --junk-paths youtube-dl youtube_dl/__main__.py
  	echo '#!$(PYTHON)' > youtube-dl
  	cat youtube-dl.zip >> youtube-dl
  	rm youtube-dl.zip
  	chmod a+x youtube-dl

Might be less confusing if you append '.zip' in the first two commands:

  	zip --quiet youtube-dl.zip youtube_dl/*.py youtube_dl/*/*.py
  	zip --quiet --junk-paths youtube-dl.zip youtube_dl/__main__.py

When you echo the shebang overwriting the file, I was thrown off. I'm thinking, "Why did you just zip all those contents into the file to just throw them out?" Then I see the `cat` line, and it makes sense that the `zip` command appends the .zip to the end of the file.