| import importlib |
|
|
|
|
| def relative_import(parent_name, rel_modules=(), rel_classes=()): |
| """ |
| Helper function to import submodules lazily in Python 3.7+ |
| |
| Parameters |
| ---------- |
| rel_modules: list of str |
| list of submodules to import, of the form .submodule |
| rel_classes: list of str |
| list of submodule classes/variables to import, of the form ._submodule.Foo |
| |
| Returns |
| ------- |
| tuple |
| Tuple that should be assigned to __all__, __getattr__ in the caller |
| """ |
| module_names = {rel_module.split(".")[-1]: rel_module for rel_module in rel_modules} |
| class_names = {rel_path.split(".")[-1]: rel_path for rel_path in rel_classes} |
|
|
| def __getattr__(import_name): |
| |
|
|
| |
| if import_name in module_names: |
| rel_import = module_names[import_name] |
| return importlib.import_module(rel_import, parent_name) |
|
|
| |
| if import_name in class_names: |
| rel_path_parts = class_names[import_name].split(".") |
| rel_module = ".".join(rel_path_parts[:-1]) |
| class_name = import_name |
| class_module = importlib.import_module(rel_module, parent_name) |
| return getattr(class_module, class_name) |
|
|
| raise AttributeError( |
| "module {__name__!r} has no attribute {name!r}".format( |
| name=import_name, __name__=parent_name |
| ) |
| ) |
|
|
| __all__ = list(module_names) + list(class_names) |
|
|
| def __dir__(): |
| return __all__ |
|
|
| return __all__, __getattr__, __dir__ |
|
|
