面向对象编程

class Student(object): 
#object 表示该类从哪个类继承下来的 
#·如果没有合适的继承类，就使用object类，这是所有类最终都会继承的类
    def __init__(self, name, score):
        self.name = name
        self.__score = score
    def get_score(self):
        return self.__score
    def set_score(self, score):
        self.__score = score
    def print_score(self):
        print(‘%s: %s‘ % (self.name, self.__score))

#实例
bart = Student(‘Bart Simpson‘, 59)
bart.print_score()
print(bart.name)
print(bart.get_score())
#print(bart.__score)
print(bart._Student__score)

class Animal(object):
    def run(self):
        print(‘Animal is running...‘)

class Dog(Animal):
    def run(self):
        print(‘Dog is running...‘)
    def eat(self):
        print(‘Eating meat...‘)

d = Dog()
d.run()

print(isinstance(d, Animal))
print(isinstance(d, Dog))

class Animal(object):
    def run(self):
        print(‘Animal is running...‘)

class Dog(Animal):
    def run(self):
        print(‘Dog is running...‘)
    def eat(self):
        print(‘Eating meat...‘)

d = Dog()
d.run()

print(isinstance(d, Animal))
print(isinstance(d, Dog))

#type
print(type(123))
print(type(Dog))
print(type(123) == int)

import types

def fn():
    pass

print(type(fn) == types.FunctionType)
print(type(lambda x : x) == types.LambdaType)

#isinstance
print(isinstance(d, Dog))

print(isinstance(‘a‘, str))

#是否是某些类型中的一种
print(isinstance([1, 2, 3], (list, tuple)))

#dir 获得一个对象的所有属性和方法
print(dir(d))


#getattr()、setattr()以及hasattr()
class MyObject(object):
    def __init__(self):
        self.x = 9
    def power(self):
        return self.x * self.x

obj = MyObject()

print(hasattr(obj, ‘x‘))
print(setattr(obj, ‘y‘, 19))
print(getattr(obj, ‘y‘))
print(getattr(obj, ‘z‘, 404)) #如果不存在返回默认值404

print(hasattr(obj, ‘power‘))
print(getattr(obj, ‘power‘))