How can I save a "complete" HTML file as single file?

I have made a python script for this. Up to now, it covers my own needs perfectly. Hopes to be useful.

https://github.com/zTrix/webpage2html

Safari (on both Windows and Mac) can create .webarchive files.

Link:
http://en.wikipedia.org/wiki/Webarchive

MHTML is the format for this.

http://en.wikipedia.org/wiki/MHTML

This web extension might help you.

https://github.com/gildas-lormeau/SingleFile

"It helps you to save a complete web page into a single HTML file."

It is available for almost all popular browsers.