Coiby

@Hasset I'm sorry, but what I mean is that you add debugging code and run the program again to print `COURSE`.

@Hasset Thanks for your feedback. I've confirmed this bug. It's because there's no hyperlink, i.e., no href attribute for some courses which haven't started yet. A temporarily solution is to...

@Hasset I've adopted a solution from iemejia/edx-downloader. But only edx-dl.py has been updated. Standalone packages will be updated a few days later.