import os
from smqtk.utils.plugin import get_plugins
from ._interface_nn_index import NearestNeighborsIndex
__all__ = [
'NearestNeighborsIndex', 'get_nn_index_impls',
]
[docs]def get_nn_index_impls(reload_modules=False):
"""
Discover and return discovered ``NearestNeighborsIndex`` classes. Keys in
the returned map are the names of the discovered classes, and the paired
values are the actual class type objects.
We search for implementation classes in:
- modules next to this file this function is defined in (ones that
begin with an alphanumeric character),
- python modules listed in the environment variable ``NN_INDEX_PATH``
- This variable should contain a sequence of python module
specifications, separated by the platform specific PATH
separator character (``;`` for Windows, ``:`` for unix)
Within a module we first look for a helper variable by the name
``NN_INDEX_CLASS``, which can either be a single class object or
an iterable of class objects, to be specifically exported. If the variable
is set to None, we skip that module and do not import anything. If the
variable is not present, we look at attributes defined in that module for
classes that descend from the given base class type. If none of the above
are found, or if an exception occurs, the module is skipped.
:param reload_modules: Explicitly reload discovered modules from source.
:type reload_modules: bool
:return: Map of discovered class object of type ``NearestNeighborsIndex``
whose keys are the string names of the classes.
:rtype: dict[str, type]
"""
this_dir = os.path.abspath(os.path.dirname(__file__))
env_var = "NN_INDEX_PATH"
helper_var = "NN_INDEX_CLASS"
return get_plugins(__name__, this_dir, env_var, helper_var,
NearestNeighborsIndex, reload_modules=reload_modules)