Factory Pattern of Design Patterns

1. Before talking about the factory pattern, implement an interface through two methods

#Two methods implemented by the interface 
class Payment:
     def pay(self,money):
         #Throw an exception when the subclass calls the pay method. If the subclass calls this method, it must implement this method first. 
        raise NotImplementedError
 class Alipay(Payment) :
     def pay(self,money):
         print ( ' Use Ali to pay %s ' % money)

from abc import ABCMeta,abstractmethod
class Payment(metaclass=ABCMeta):
    @abstractmethod
    def pay(self,money): #implemented
         by the method provided by the system If the subclass calls this method, it must implement this method before calling 
        pass 
class Alipay(Payment):
     def pay(self,money):
         print ( ' Use Ali paid %s ' %money)

2. Implementation of the Factory Pattern

from abc import abstractmethod,ABCMeta
 class Payment(metaclass= ABCMeta): #Interface 
　　class, providing payment methods
    @abstractmethod
    def pay(self,money):
         raise NotImplementedError
 class Alipayment(Payment): #To 
　　implement the interface class, the pay method of the interface must be implemented
     def pay(self,money):
         print ( ' Ali paid %s yuan ' % money)
 class Applepayment (Payment):
     def pay(self,money):
         print ( ' Apple paid %s yuan ' % money)
 class Wechatpaymet(Payment):
     def pay(self,money):
         print ( ' Wechat paid %s yuan ' % money)
 classFactory:
         #Factory class, hiding the details of object creation 
    @classmethod
     def create_payment(self,args):
         if args == ' ali ' :
             return Alipayment()
         elif args == ' apple ' :
             return Applepayment()
         elif args == ' wechat ' :
             return Wechatpaymet()
         else :
             raise NameError(args)
payment = Factory.create_payment('ali')
payment.pay(50)