metron_shared.structures module

This module provides data structures/patterns (classes or decorators).

class metron_shared.structures.Singleton(decorated_object: Any)

Bases: object

Represents singleton data pattern applicable on class / function / method . When applied on a class, only one instance of the class is allowed for whole program lifespan. When applied on a function / method , only one call is allowed for whole program lifespan. The decorator can be applied on more classes / functions / methods, not only on one object of the program. It does not change decorated object.

_called

Set data structure which keeps one use across classes / functions / methods.

Type:

Set[Any]

_function

Class / function / method on which the decorator is applied.

Type:

Any

__annotations__ = {'_called': typing.Set[typing.Any]}

__call__(*args: Any, **kwargs: Any) → Any

It checks if decorated object was not already instantiated or called. If does not, it allows to create / call it. The method is called when decorator is applied on class / function / method.

Parameters:

• *args (Any) – Positional arguments.

• **kwargs (Any) – Key-worded arguments.

Returns (Typing.Any): Decorated object itself without change.

Exceptions:

Exception: Violence of singleton paradigm of decorated object.

__get__(instance: Any, owner: Any) → Any

The method is needed to work with class method.

Parameters:

• instance (Any) – Class instance.

• owner (Any) – Instance class owner.

Returns (typing.Any):

Exceptions:

Exception: Violence of singleton paradigm of decorated object.

__init__(decorated_object: Any)

Saves decorated object as attribute, for later lookup.

Parameters:

decorated_object (Any) – Decorated object.

_called: Set[Any] = {<function set_hydra_config>}