Previously if submodules were imported after the plugin/symbol __path__s had
been set, it would only use the __path__s from the constants module.
We now use the parent module's __path__s to ensure we get the right
sub__path__s.
This seems better/more flexible than changing the original constants
(since they'd no longer be constant) and allows people more chance to
override things. It brings with it potential confusion as a local
plugin directory will need __init__ files with this magic to allow the
core modules to run (since they come first in the path list).
This should have no impact functionality-wise.
The statistics plugin was left out a) as an example and b) because it
was committed by mistake in the first place and was never meant to be a
real plugin.
This includes:
* Better ways of checking empty lists
* Not shadowing builtin functions like filter
* Preventing invalid slash warnings by marking strings as regexps
* Removing unnecessary brackets
* Lowercase variable names
* Adding/updating parameters in docstrings
* Removing unused code (lines not chunks)
* Change in not a member tests
* Changing some methods to static
* Shorting range membership checks
* Missing parameters
* Make some exception handlers more specific
* Don't define a lambda to a variable
* A few more instance checks to help type checkers
Relented on the strict import of direct objects/classes for the typing
module only. Typing module components can be directly imported because
it makes the code really painful to read and write otherwise.
This is still in-line with the python style guide adopted from Google at
http://google.github.io/styleguide/pyguide.html section 2.2.
Mike Auty