| | 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__ |
| |
|
