dynamic_imports

This module provides utilities for dynamic imports, allowing optional imports and importing modules from paths.

OptionalImports dataclass

Handles optional imports, allowing modules to be imported only if they are available.

Attributes:

Name	Type	Description
imports	dict[str, object]	A dictionary to store the imported modules.

Example

from lighter.utils.dynamic_imports import OPTIONAL_IMPORTS
writer = OPTIONAL_IMPORTS["tensorboard"].SummaryWriter()

Source code in lighter/utils/dynamic_imports.py

@dataclass
class OptionalImports:
    """
    Handles optional imports, allowing modules to be imported only if they are available.

    Attributes:
        imports: A dictionary to store the imported modules.

    Example:
        ```
        from lighter.utils.dynamic_imports import OPTIONAL_IMPORTS
        writer = OPTIONAL_IMPORTS["tensorboard"].SummaryWriter()
        ```
    """

    imports: dict[str, object] = field(default_factory=dict)

    def __getitem__(self, module_name: str) -> object:
        """
        Get the imported module by name, importing it if necessary.

        Args:
            module_name: Name of the module to import.

        Raises:
            ImportError: If the module is not available.

        Returns:
            object: The imported module.
        """
        """Get the imported module by name.

        Args:
            module_name: Name of the module to import.

        Raises:
            ImportError: If the module is not available.

        Returns:
            Imported module.
        """
        if module_name not in self.imports:
            self.imports[module_name], module_available = optional_import(module_name)
            if not module_available:
                raise ImportError(f"'{module_name}' is not available. Make sure that it is installed and spelled correctly.")
        return self.imports[module_name]

__getitem__(module_name)

Get the imported module by name, importing it if necessary.

Parameters:

Name	Type	Description	Default
module_name	str	Name of the module to import.	required

Raises:

Type	Description
ImportError	If the module is not available.

Returns:

Name	Type	Description
object	object	The imported module.

Source code in lighter/utils/dynamic_imports.py

def __getitem__(self, module_name: str) -> object:
    """
    Get the imported module by name, importing it if necessary.

    Args:
        module_name: Name of the module to import.

    Raises:
        ImportError: If the module is not available.

    Returns:
        object: The imported module.
    """
    """Get the imported module by name.

    Args:
        module_name: Name of the module to import.

    Raises:
        ImportError: If the module is not available.

    Returns:
        Imported module.
    """
    if module_name not in self.imports:
        self.imports[module_name], module_available = optional_import(module_name)
        if not module_available:
            raise ImportError(f"'{module_name}' is not available. Make sure that it is installed and spelled correctly.")
    return self.imports[module_name]

import_module_from_path(module_name, module_path)

Import a module from a given path and assign it a specified name.

Parameters:

Name	Type	Description	Default
module_name	str	Name to assign to the imported module.	required
module_path	str	Path to the module being imported.	required

Raises:

Type	Description
ValueError	If the module has already been imported.
FileNotFoundError	If the __init__.py file is not found in the module path.

Source code in lighter/utils/dynamic_imports.py

def import_module_from_path(module_name: str, module_path: str) -> None:
    """
    Import a module from a given path and assign it a specified name.

    Args:
        module_name: Name to assign to the imported module.
        module_path: Path to the module being imported.

    Raises:
        ValueError: If the module has already been imported.
        FileNotFoundError: If the `__init__.py` file is not found in the module path.
    """
    # Based on https://stackoverflow.com/a/41595552.

    if module_name in sys.modules:
        logger.warning(f"{module_name} has already been imported as module.")
        return

    module_path = Path(module_path).resolve() / "__init__.py"
    if not module_path.is_file():
        raise FileNotFoundError(f"No `__init__.py` in `{module_path}`.")
    spec = importlib.util.spec_from_file_location(module_name, str(module_path))
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    sys.modules[module_name] = module
    logger.info(f"Imported {module_path.parent} as module '{module_name}'.")