Merge pull request #4132 from raulG91/raulG91

#23 - Python

Author: Roswell468

Roadmap/23 - SINGLETON/python/raulG91.py

@@ -0,0 +1,53 @@
+class SingletonMeta(type):
+
+    _instances = {}
+    def __call__(cls,*args,**kwargs):
+        if cls not in cls._instances:
+            instance = super().__call__(*args,**kwargs)
+            cls._instances[cls] = instance
+        return cls._instances[cls]    
+    def clear(cls):
+        cls._instances.pop(cls)
+
+class Singleton(metaclass=SingletonMeta):
+    def syHello(self):
+        print("Hello from Singleton class") 
+
+s1 = Singleton()
+s2 = Singleton() 
+
+if id(s1) == id(s2):
+    print("Both instances have same id")
+else:
+    print("Intances are different")    
+
+class User(metaclass=SingletonMeta):
+    def __init__(self,id,username,name,email):
+        self.id = id
+        self.username = username
+        self.name = name
+        self.email = email 
+    def get_name(self):
+        return self.name
+    def get_id(self):
+        return self.id
+    def get_username(self):
+        return self.username     
+    def get_email(self):
+        return self.email
+    def close_session(self):
+        User.clear()
+ 
+
+user = User(1,"user1","Juan","[email protected]")
+id1 = id(user)
+print(f'Id for object: {id1}')
+print(f'User Id {user.get_id()}')
+print(f'User name {user.get_name()}')
+user.close_session()
+user2 = User(2,"user2","Luna","[email protected]")
+id2 = id(user2)
+print(f'Id for object: {id2}')
+print(f'User Id {user2.get_id()}')
+print(f'User name {user2.get_name()}')
+user2.close_session()