acmecse.helpers.Singleton.Singleton

class documentation

class Singleton(type): (source)

Singleton metaclass.

This class implements the Singleton design pattern as a metaclass.

Attention

Classes using this metaclass will never be able to have more than one instance.

Also, instances will not be garbage collected until the program ends.

Example

Method	`__call__`	Override the __call__ method to control the instantiation of classes using this metaclass.
Class Variable	`_instances`	Dictionary to hold the single instances of the classes using this metaclass.

def __call__(cls, *args: Any, **kwargs: Any) -> object: (source) ¶

Override the __call__ method to control the instantiation of classes using this metaclass.

Parameters
cls	Undocumented
*args:`Any`	Positional arguments to pass to the class constructor.
**kwargs:`Any`	Keyword arguments to pass to the class constructor.

Returns
`object`	The single instance of the class.

_instances: dict[type, object] = (source) ¶

Dictionary to hold the single instances of the classes using this metaclass.