If you have the means to run python locally,
just create a new folder and drop the program
file and script file into it. Then, create three
blank html files named 'input.html', 'output.html',
and 'intermediate.html' (all lowercase) and you're set.
When making your new page of images, either use the 'albumgen.css' file
as the stylesheet, copy its contents into your own local stylesheet,
or just include its contents between some '<style></style>' elements in your
'<head></head>' elements.
If you dont have the means to run python, I'd recommend pythonanywhere.com.
accounts are free and you can pretty easily replicate
the same process in a virtual environment.
In the video, I am using Spyder
(part of my Anaconda installation) for python
and the now-defunct Atom for text editing.