utils_imports.py

import importlib, pkgutil

# https://packaging.python.org/guides/creating-and-discovering-plugins/
def iter_namespace (pkg_or_path, prefix = '', **kwds):
  # Specifying the second argument (prefix) to iter_modules makes the
  # returned name an absolute name instead of a relative one. This
  # allows import_module to work without having to do additional
  # modification to the name.
  is_path = pkg_or_path is None or isinstance (pkg_or_path, list)
  path, prefix = \
    (pkg_or_path, prefix) if is_path else \
    (pkg_or_path.__path__, prefix if prefix is not '' else pkg_or_path.__name__ + ".")
  return pkgutil.walk_packages (path, prefix, **kwds)

def load_submodules (root, modules = None, prefix = '', **kwds):
  return {
    name: importlib.import_module (name)
    for _finder, name, _ispkg in iter_namespace (root, prefix = prefix, **kwds)
    if (modules is None or name in modules) and name.startswith (prefix)
  }