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Registry

Bases: NestedDict

Registry for components.

Registry provides 3 core functionalities:

  • Register a new component.
  • Lookup for a component.
  • Build a component.

To facilitate the usage scenario, registry is designed to be a decorator. You could register a component by simply calling registry.register, and it will be registered with its name. You may also specify the name of the component by calling registry.register(name="ComponentName").

build makes it easy to construct a component from a configuration. build automatically determines the component to construct by the name field in the configuration. So you could either call registry.build(config) or registry.build(**config). Beyond this, build is just a syntax sugar for registry.init(registry.lookup(name), *args, **kwargs).

lookup is used to lookup for a component by its name. By default, lookup internally calls NestedDict.get, but you may override it to provide more functionalities.

init is used to construct a component. By default, init internally calls cls(*args, **kwargs), but you may override it to provide more functionalities.

Notes

Registry inherits from NestedDict.

Therefore, Registry comes in a nested structure by nature. You could create a sub-registry by simply calling registry.sub_registry = Registry, and access through registry.sub_registry.register().

Examples:

Python Console Session
>>> registry = Registry()
>>> @registry.register
... @registry.register("Module1")
... class Module:
...     def __init__(self, a, b):
...         self.a = a
...         self.b = b
>>> module = registry.register(Module, "Module2")
>>> registry
Registry(
  ('Module1'): <class 'chanfig.registry.Module'>
  ('Module'): <class 'chanfig.registry.Module'>
  ('Module2'): <class 'chanfig.registry.Module'>
)
>>> module = registry.register(Module, "Module")
Traceback (most recent call last):
ValueError: Component with name Module already registered.
>>> registry.lookup("Module")
<class 'chanfig.registry.Module'>
>>> config = {"module": {"name": "Module", "a": 1, "b": 2}}
>>> # registry.register(Module)
>>> module = registry.build(config["module"])
>>> type(module)
<class 'chanfig.registry.Module'>
>>> module.a
1
>>> module.b
2
Source code in chanfig/registry.py
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class Registry(NestedDict):
    """
    `Registry` for components.

    Registry provides 3 core functionalities:

    - Register a new component.
    - Lookup for a component.
    - Build a component.

    To facilitate the usage scenario, `registry` is designed to be a decorator.
    You could register a component by simply calling `registry.register`, and it will be registered with its name.
    You may also specify the name of the component by calling `registry.register(name="ComponentName")`.

    `build` makes it easy to construct a component from a configuration.
    `build` automatically determines the component to construct by the `name` field in the configuration.
    So you could either call `registry.build(config)` or `registry.build(**config)`.
    Beyond this, `build` is just a syntax sugar for `registry.init(registry.lookup(name), *args, **kwargs)`.

    `lookup` is used to lookup for a component by its name.
    By default, `lookup` internally calls `NestedDict.get`, but you may override it to provide more functionalities.

    `init` is used to construct a component.
    By default, `init` internally calls `cls(*args, **kwargs)`, but you may override it to provide more functionalities.

    Notes:
        `Registry` inherits from `NestedDict`.

        Therefore, `Registry` comes in a nested structure by nature.
        You could create a sub-registry by simply calling `registry.sub_registry = Registry`,
        and access through `registry.sub_registry.register()`.

    Examples:
        >>> registry = Registry()
        >>> @registry.register
        ... @registry.register("Module1")
        ... class Module:
        ...     def __init__(self, a, b):
        ...         self.a = a
        ...         self.b = b
        >>> module = registry.register(Module, "Module2")
        >>> registry
        Registry(
          ('Module1'): <class 'chanfig.registry.Module'>
          ('Module'): <class 'chanfig.registry.Module'>
          ('Module2'): <class 'chanfig.registry.Module'>
        )
        >>> module = registry.register(Module, "Module")
        Traceback (most recent call last):
        ValueError: Component with name Module already registered.
        >>> registry.lookup("Module")
        <class 'chanfig.registry.Module'>
        >>> config = {"module": {"name": "Module", "a": 1, "b": 2}}
        >>> # registry.register(Module)
        >>> module = registry.build(config["module"])
        >>> type(module)
        <class 'chanfig.registry.Module'>
        >>> module.a
        1
        >>> module.b
        2
    """

    override: bool = False

    def __init__(self, override: bool | None = None, fallback: bool | None = None):
        super().__init__(fallback=fallback)
        if override is not None:
            self.setattr("override", override)

    def register(self, component: Any = None, name: Any | None = None, override: bool = False) -> Callable:
        r"""
        Register a new component.

        Args:
            component: The component to register.
            name: The name of the component.

        Returns:
            component: The registered component.
                Registered component are expected to be `Callable`.

        Raises:
            ValueError: If the component with the same name already registered and `Registry.override=False`.

        Examples:
            >>> registry = Registry()
            >>> @registry.register
            ... @registry.register("Module1")
            ... class Module:
            ...     def __init__(self, a, b):
            ...         self.a = a
            ...         self.b = b
            >>> module = registry.register(Module, "Module2")
            >>> registry
            Registry(
              ('Module1'): <class 'chanfig.registry.Module'>
              ('Module'): <class 'chanfig.registry.Module'>
              ('Module2'): <class 'chanfig.registry.Module'>
            )
        """

        if name in self and not (override or self.override):
            raise ValueError(f"Component with name {name} already registered.")

        # Registry.register()
        if name is not None:
            self.set(name, component)
            return component
        # @Registry.register
        if callable(component) and name is None:
            self.set(component.__name__, component)
            return component

        # @Registry.register()
        def decorator(name: Any | None = None):
            @wraps(self.register)
            def wrapper(component):
                if name is None:
                    self.set(component.__name__, component)
                else:
                    self.set(name, component)
                return component

            return wrapper

        return decorator(component)

    def lookup(self, name: str) -> Any:
        r"""
        Lookup for a component.

        Args:
            name:

        Returns:
            (Any): The component.

        Raises:
            KeyError: If the component is not registered.

        Examples:
            >>> registry = Registry()
            >>> @registry.register
            ... class Module:
            ...     def __init__(self, a, b):
            ...         self.a = a
            ...         self.b = b
            >>> registry.lookup("Module")
            <class 'chanfig.registry.Module'>
        """

        return self[name]

    @staticmethod
    def init(cls: Callable, *args: Any, **kwargs: Any) -> Any:  # pylint: disable=W0211
        r"""
        Constructor of component.

        Args:
            cls: The component to construct.
            *args: The arguments to pass to the component.
            **kwargs: The keyword arguments to pass to the component.

        Returns:
            (Any):

        Examples:
            >>> class Module:
            ...     def __init__(self, a, b):
            ...         self.a = a
            ...         self.b = b
            >>> kwargs = {"a": 1, "b": 2}
            >>> module = Registry.init(Module, **kwargs)
            >>> type(module)
            <class 'chanfig.registry.Module'>
            >>> module.a
            1
            >>> module.b
            2
        """

        return cls(*args, **kwargs)

    def build(self, name: str | Mapping, *args: Any, **kwargs: Any) -> Any:
        r"""
        Build a component.

        Args:
            name (str | Mapping):
                If its a `Mapping`, it must contain `"name"` as a member, the rest will be treated as `**kwargs`.
                Note that values in `kwargs` will override values in `name` if its a `Mapping`.
            *args: The arguments to pass to the component.
            **kwargs: The keyword arguments to pass to the component.

        Returns:
            (Any):

        Raises:
            KeyError: If the component is not registered.

        Examples:
            >>> registry = Registry()
            >>> @registry.register
            ... class Module:
            ...     def __init__(self, a, b):
            ...         self.a = a
            ...         self.b = b
            >>> config = {"module": {"name": "Module", "a": 1, "b": 2}}
            >>> # registry.register(Module)
            >>> module = registry.build(**config["module"])
            >>> type(module)
            <class 'chanfig.registry.Module'>
            >>> module.a
            1
            >>> module.b
            2
            >>> module = registry.build(config["module"], a=2)
            >>> module.a
            2
        """

        if isinstance(name, Mapping):
            name = deepcopy(name)
            name, kwargs = name.pop("name"), dict(name, **kwargs)  # type: ignore
        return self.init(self.lookup(name), *args, **kwargs)  # type: ignore

build(name, *args, **kwargs)

Build a component.

Parameters:

Name Type Description Default
name str | Mapping

If its a Mapping, it must contain "name" as a member, the rest will be treated as **kwargs. Note that values in kwargs will override values in name if its a Mapping.

 required
*args Any

The arguments to pass to the component.

 ()
**kwargs Any

The keyword arguments to pass to the component.

 {}

Returns:

Type Description
Any

Raises:

Type Description
KeyError

If the component is not registered.

Examples:

Python Console Session
>>> registry = Registry()
>>> @registry.register
... class Module:
...     def __init__(self, a, b):
...         self.a = a
...         self.b = b
>>> config = {"module": {"name": "Module", "a": 1, "b": 2}}
>>> # registry.register(Module)
>>> module = registry.build(**config["module"])
>>> type(module)
<class 'chanfig.registry.Module'>
>>> module.a
1
>>> module.b
2
>>> module = registry.build(config["module"], a=2)
>>> module.a
2
Source code in chanfig/registry.py
Python
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def build(self, name: str | Mapping, *args: Any, **kwargs: Any) -> Any:
    r"""
    Build a component.

    Args:
        name (str | Mapping):
            If its a `Mapping`, it must contain `"name"` as a member, the rest will be treated as `**kwargs`.
            Note that values in `kwargs` will override values in `name` if its a `Mapping`.
        *args: The arguments to pass to the component.
        **kwargs: The keyword arguments to pass to the component.

    Returns:
        (Any):

    Raises:
        KeyError: If the component is not registered.

    Examples:
        >>> registry = Registry()
        >>> @registry.register
        ... class Module:
        ...     def __init__(self, a, b):
        ...         self.a = a
        ...         self.b = b
        >>> config = {"module": {"name": "Module", "a": 1, "b": 2}}
        >>> # registry.register(Module)
        >>> module = registry.build(**config["module"])
        >>> type(module)
        <class 'chanfig.registry.Module'>
        >>> module.a
        1
        >>> module.b
        2
        >>> module = registry.build(config["module"], a=2)
        >>> module.a
        2
    """

    if isinstance(name, Mapping):
        name = deepcopy(name)
        name, kwargs = name.pop("name"), dict(name, **kwargs)  # type: ignore
    return self.init(self.lookup(name), *args, **kwargs)  # type: ignore

init(*args, **kwargs) staticmethod

Constructor of component.

Parameters:

Name Type Description Default
cls Callable

The component to construct.

 required
*args Any

The arguments to pass to the component.

 ()
**kwargs Any

The keyword arguments to pass to the component.

 {}

Returns:

Type Description
Any

Examples:

Python Console Session
>>> class Module:
...     def __init__(self, a, b):
...         self.a = a
...         self.b = b
>>> kwargs = {"a": 1, "b": 2}
>>> module = Registry.init(Module, **kwargs)
>>> type(module)
<class 'chanfig.registry.Module'>
>>> module.a
1
>>> module.b
2
Source code in chanfig/registry.py
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@staticmethod
def init(cls: Callable, *args: Any, **kwargs: Any) -> Any:  # pylint: disable=W0211
    r"""
    Constructor of component.

    Args:
        cls: The component to construct.
        *args: The arguments to pass to the component.
        **kwargs: The keyword arguments to pass to the component.

    Returns:
        (Any):

    Examples:
        >>> class Module:
        ...     def __init__(self, a, b):
        ...         self.a = a
        ...         self.b = b
        >>> kwargs = {"a": 1, "b": 2}
        >>> module = Registry.init(Module, **kwargs)
        >>> type(module)
        <class 'chanfig.registry.Module'>
        >>> module.a
        1
        >>> module.b
        2
    """

    return cls(*args, **kwargs)

lookup(name)

Lookup for a component.

Parameters:

Name Type Description Default
name str
required

Returns:

Type Description
Any

The component.

Raises:

Type Description
KeyError

If the component is not registered.

Examples:

Python Console Session
>>> registry = Registry()
>>> @registry.register
... class Module:
...     def __init__(self, a, b):
...         self.a = a
...         self.b = b
>>> registry.lookup("Module")
<class 'chanfig.registry.Module'>
Source code in chanfig/registry.py
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def lookup(self, name: str) -> Any:
    r"""
    Lookup for a component.

    Args:
        name:

    Returns:
        (Any): The component.

    Raises:
        KeyError: If the component is not registered.

    Examples:
        >>> registry = Registry()
        >>> @registry.register
        ... class Module:
        ...     def __init__(self, a, b):
        ...         self.a = a
        ...         self.b = b
        >>> registry.lookup("Module")
        <class 'chanfig.registry.Module'>
    """

    return self[name]

register(component=None, name=None, override=False)

Register a new component.

Parameters:

Name Type Description Default
component Any

The component to register.

 None
name Any | None

The name of the component.

 None

Returns:

Name Type Description
component Callable

The registered component. Registered component are expected to be Callable.

Raises:

Type Description
ValueError

If the component with the same name already registered and Registry.override=False.

Examples:

Python Console Session
>>> registry = Registry()
>>> @registry.register
... @registry.register("Module1")
... class Module:
...     def __init__(self, a, b):
...         self.a = a
...         self.b = b
>>> module = registry.register(Module, "Module2")
>>> registry
Registry(
  ('Module1'): <class 'chanfig.registry.Module'>
  ('Module'): <class 'chanfig.registry.Module'>
  ('Module2'): <class 'chanfig.registry.Module'>
)
Source code in chanfig/registry.py
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def register(self, component: Any = None, name: Any | None = None, override: bool = False) -> Callable:
    r"""
    Register a new component.

    Args:
        component: The component to register.
        name: The name of the component.

    Returns:
        component: The registered component.
            Registered component are expected to be `Callable`.

    Raises:
        ValueError: If the component with the same name already registered and `Registry.override=False`.

    Examples:
        >>> registry = Registry()
        >>> @registry.register
        ... @registry.register("Module1")
        ... class Module:
        ...     def __init__(self, a, b):
        ...         self.a = a
        ...         self.b = b
        >>> module = registry.register(Module, "Module2")
        >>> registry
        Registry(
          ('Module1'): <class 'chanfig.registry.Module'>
          ('Module'): <class 'chanfig.registry.Module'>
          ('Module2'): <class 'chanfig.registry.Module'>
        )
    """

    if name in self and not (override or self.override):
        raise ValueError(f"Component with name {name} already registered.")

    # Registry.register()
    if name is not None:
        self.set(name, component)
        return component
    # @Registry.register
    if callable(component) and name is None:
        self.set(component.__name__, component)
        return component

    # @Registry.register()
    def decorator(name: Any | None = None):
        @wraps(self.register)
        def wrapper(component):
            if name is None:
                self.set(component.__name__, component)
            else:
                self.set(name, component)
            return component

        return wrapper

    return decorator(component)
Last update: 2023-07-20 17:14:16