Chapter XIII produce, control of the class metaclass

Chapter XIII produce, control of the class metaclass

A custom metaclass

Description : A class inherits this class type called metaclass

The purpose : to control the production of class, you can control the class name, parent class can inherit control of the control class name space

Second, write a custom metaclass

• The class name of the control class

  class Mymeta(type):
      # def __init__(self,*args,**kwargs):
      def __init__(self,name,bases,dic):
          # self 就是Person类
          print(name)
          print(bases)
          print(dic)
          # 练习一:加限制 控制类名必须以sb开头
          if not name.startswith('sb'):
              raise Exception('类名没有以sb开头')

• The class must annotate

  class Mymeta(type):
      def __init__(self,name,bases,dic):
          print(self.__dict__['__doc__'])
          doc=self.__dict__['__doc__']
          if not doc:
              #没有加注释
              raise Exception('你的类没有加注释')
  class Person(object,metaclass=Mymeta):
      '''
      我加了注释
      '''
      school='oldboy'
      def __init__(self,name):
          self.name=name
      def score(self):
          print('分数是100')