zhuquan0 2020-05-25
#定义一个类Student class Student(object): pass #给类增加一个属性name Student.name = ‘xm‘ print Student.name # xm #给类增加一个方法set_age def set_age(self,age): self.age = age Student.set_age = set_age s = Student() s.set_age(20) print s.age #20 #给实例属性增加一个属性: s1 = Student() s1.name = ‘xh‘ print s1.name #xh #给实例属性增加一个方法: def set_score(self,score): self.score = score from types import MethodType s1.set_score = MethodType(set_score,s1) s1.set_score(88) print s1.score #88 #而其它的实例对象并没有set_score方法 print s.score #‘Student‘ object has no attribute ‘score‘
class Singleton: def __new__: # 关键在于这,每一次实例化的时候,我们都只会返回这同一个instance对象 if not hasattr: cls.instance =