So here's how I read some code to myself yesterday:
Okay, first step here is we get a list of graphs to draw, it's a generator.
We go through each graph figuring out which datafiles we need to load so we
only load them once.
This we know is working so far because of print statements, showing two
datafiles in this case.
Now the next step, we're going through the generator again,... oh.
Yeah, you can't use a generator twice in Python and I knew it, but I didn't remember it until I heard myself speaking out loud. What's up with that?