pypack.singleton 1.0.0

pypack.singleton is singleton design pattern for python3, simple to use and customize

Installation:

pip install pypack.singleton

Import and Example Usage:

from pypack.singleton import Singleton

@Singleton
class ASingletonClass: pass

# ASingletonClass now is a singleton

Method List of Singleton:

# clear all singleton instances
Singleton.clear() -> None:

# remove class i from Singleton
Singleton.remove(i : Singleton) -> None:

# get instance of singleton class
Singleton.get(i : Singleton) -> Union(None, Any)

# Iterator of each class in singleton
Singleton.classes() -> Singleton.SingletonClassesIterator:

# Iterator of each instance in singleton
Singleton.instances() -> Singleton.SingletonInstancesIteratorL

# Iterator of Pair<Class, Instance> in singleton
Singleton.pairs() -> Singleton.SingletonPairsIterator:

Method List of Singleton signed Class:

suppose you have marked a class as a Singleton

@Singleton
class MySingleton:
    """Just a custom Singleton class"""

    def __init__ (self, *args, **kwargs):
        pass

    def __call__ (self, *args, **kwargs):
        pass

you can interact with your singleton in this way:

# MySingleton in Singleton.classes() == False (Not Created yet)

s1 = MySingleton() # Singleton is actually created here
                   # and MySingleton.__init__(s1) is called

# MySingleton in Singleton.classes() == True (Created)

s2 = MySingleton() # Singleton of MySingleton already
                   # exists so, MySingleton.__call__(s2) is called
                   # if MySingleton.__call__ is missing nothing is called

# s1 == s2 -> True

# Retrive already created instance or None
s3 = MySingleton.get_instance() -> Union (None, Any):

# s1 == s2 == s3