cant handle the '/' character in name

[teicheld]

Traceback (most recent call last):
File "edx-dl.py", line 199, in
run()
File "/home/fe/.local/lib/python3.7/site-packages/click/core.py", line 1137, in call
return self.main(*args, **kwargs)
File "/home/fe/.local/lib/python3.7/site-packages/click/core.py", line 1062, in main
rv = self.invoke(ctx)
File "/home/fe/.local/lib/python3.7/site-packages/click/core.py", line 1404, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/fe/.local/lib/python3.7/site-packages/click/core.py", line 763, in invoke
return __callback(*args, **kwargs)[
File "edx-dl.py", line 196, in run
course()
File "edx-dl.py", line 46, in call
self.mkdir(sub_title)
File "edx-dl.py", line 89, in mkdir
os.mkdir(path)
FileNotFoundError: [Errno 2] No such file or directory: '3_Lesson_3:_Path_coverage_and_MC/DC'

We cannot escape the '/' character
I would suggest to replace the '/' character by '|'

[antinucleon]

Feel free to submit PR to change https://github.com/antinucleon/edx-dl/blob/main/edx-dl.py#L85 accordingly.