Python Package Guidelines
1 Package Naming
For libraries, use python-modulename. For applications, use the program name. In either case, the name should be entirely lowercase.
Python2 libraries should instead be named python2-modulename.
2 File Placement
Most python packages are installed with the distutils system using setup.py, which places files under /usr/lib/python<python version>/site-packages/pkgname directory.
The --optimize parameter compiles .pyo files so they can be tracked by pacman.
In most cases, you should put any in the arch array since most Python packages are architecture independent.
Please do not install a directory named just tests, as it easily conflicts with other python packages. (Like /usr/lib/python2.7/site-packages/tests/)
An example PKGBUILD can be found at /usr/share/pacman/PKGBUILD-python.proto, which is in the abs package.