Not sure what happened. I reinstalled and the issue went away.

For the record, it may have been that the py files hadn't been compiled, and therefore Python had to do work to create the pyc files each time (especially relevant if you installed to somewhere where you don't normally have write permission). Running a python -v can sometimes give this away.

Good point. In this case, missing pyc files were not the issue. I had checked that they existed (in the virtualenv within my home directory). The slow times persisted after many consecutive runs as well. This was a pip install -e within the git repo.

I had the same problem. .pyc files weren't the issue. The solution is documented here:

http://stackoverflow.com/questions/26421364/extremely-slow-import-of-matplotlib-afm

All it required was deleting ~/.cache/matplotlib.

All it required was deleting ~/.cache/matplotlib.

Thanks @mspacek. I think we should fix this - it is a wart which can be fixed without major hassle (i.e. we should version the cache).

@mspacek - would you mind opening an issue to do that?

Done. #4993