Dynamic imports

. Динам импорт из любой директории

import importlib
import sys

robot_folder_path = r'full\path\to\folder\with\packages'
module_name = 'PackageName'
file_path = f'{robot_folder_path}\\{module_name}\\__init__.py'

spec = importlib.util.spec_from_file_location(module_name, file_path)
module = importlib.util.module_from_spec(spec)
sys.modules[module_name] = module
spec.loader.exec_module(module)

init_class = module.Class_name()

loader

import importlib
import sys


def load_module_class(module_name, class_name, robot_folder_path):
    """
    module_name:    'xmlschemes.scenario'   or  'PythonEngine'
    class_name:     'Resources'             or  'Engine'
    """
    module_name = module_name.split(".")
    module = module_loader(robot_folder_path, module_name[0])
    module_class = class_loader(module, module_name, class_name)
    return module_class


def module_loader(folder_path, module_name):
    """
    folder_path = 'path\to\folder\with\packages'
    module_name = 'PythonEngine'
    """
    file_path = f'{folder_path}\\{module_name}\\__init__.py'
    spec = importlib.util.spec_from_file_location(module_name, file_path)
    module = importlib.util.module_from_spec(spec)
    sys.modules[module_name] = module
    spec.loader.exec_module(module)
    return module


def class_loader(module, module_name, class_name):
    if not isinstance(module_name, list):
        module_name = module_name.split(".")
    assert len(module_name) > 0
    if len(module_name) == 1:
        module_class = getattr(module, class_name)
        return module_class
    if len(module_name) == 2:
        module = getattr(module, module_name[1])
        module_class = getattr(module, class_name)
        return module_class
    else:
        module = getattr(module, module_name[1])
        class_loader(module, module_name[1:], class_name)

MockImporter class

import sys
import types
import importlib.abc
import importlib.machinery
import importlib.util


class MockImporter(importlib.abc.MetaPathFinder, importlib.abc.Loader):

    def __init__(self, modules):
        self.modules = modules

    def find_spec(self, fullname, path, target=None):
        print('find_spec', fullname, path)
        contents = self.modules.get(fullname)
        if contents is None:
            return None
        return importlib.machinery.ModuleSpec(
            fullname, self)

    def create_module(self, spec):
        module = types.ModuleType(spec.name)
        module.__dict__.update(self.modules[spec.name])
        return module

    def exec_module(self, module):
        pass


def main():
    modules = {
        'foo': {
            'attr': 'value',
        },
        'foo.bar': {
            'attr', 'value',
        }
    }

    sys.meta_path.append(MockImporter(modules))
    from foo import bar

if __name__ == '__main__':
    main()

Динамический импорт класса

import importlib                                        # Can't import modules which aren't in current project.

def dynamic_import(module):
    return importlib.import_module(module)

module = self.dynamic_import(path + "." + "foo")        # shold look like this: package.subpackage.subsubpackage.foo
module.main()

Динамический импорт класса (полезно для системы плагинов в питоне)

import importlib
module = importlib.import_module('app.plugins')
plugin_class = getattr(module, 'PluginName')
plugin_instance = plugin_class(*args, **kwargs) # Like standard instance = Class(params)