Package structure and startup time

[felix-andreas]

Currently every public object is exposed via the top-level __init__.py. This effects the startup time when importing latticejson as library but also the startup time of the CLI (because it is a submodule and the parent package gets always executed). Maybe it would be better to use the scipy-approach: Keep the Top-level __init__.py empty and use subpackages to import functionality. But this would be somewhat inconvenient for a user...

To solve the issue for the CLI, the cli.py could be installed separately.

Maybe the __getattr__ of PEP 562 can be used to lazy load the submodules into the top-level name space of the __init__.py.

See also:

• How to only import sub module without exec __init__.py in the package
• One class per file causes double names in python