Python正课69 —— 属性查找

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一：属性查找

class Student:
    # 1、变量的定义
    stu_school = 'oldboy'
    count = 0

    # 空对象,'egon',18,'male'
    def __init__(self, x, y, z):
        Student.count += 1

        self.stu_name = x  # 空对象.stu_name='egon'
        self.stu_age = y  # 空对象.stu_age=18
        self.stu_gender = z  # 空对象.stu_gender='male'
        # return None

    # 2、功能的定义
    def tell_stu_info(self):
        print('学生信息：名字：%s 年龄：%s 性别：%s' % (
            self.stu_name,
            self.stu_age,
            self.stu_gender
        ))

    def set_info(self, x, y, z):
        self.stu_name = x
        self.stu_age = y
        self.stu_gender = z

    def choose(self, x):
        print('正在选课')
        self.course = x


stu1_obj = Student('egon', 18, 'male')  # Student.__init__(空对象,'egon',18,'male')
stu2_obj = Student('lili', 19, 'female')
stu3_obj = Student('jack', 20, 'male')

# print(stu1_obj.count)
# print(stu2_obj.count)
# print(stu3_obj.count)

二：类中存放的是对象共有的数据与功能

1.类可以访问：

# 1.类的数据属性
print(Student.stu_school)       # oldboy

# 2.类的函数属性
print(Student.tell_stu_info)        # <function Student.tell_stu_info at 0x00F78460>
print(Student.set_info)             # <function Student.set_info at 0x01728418>

2.但其实类中的东西是给对象用的

# 1.类的数据属性是共享给所有对象用的，大家访问的地址都一样
print(id(Student.stu_school))        # 23914752

print(id(stu1_obj.stu_school))       # 23914752
print(id(stu2_obj.stu_school))       # 23914752
print(id(stu3_obj.stu_school))       # 23914752

Student.stu_school='OLDBOY'
stu1_obj.stu_school='OLDBOY'
print(stu1_obj.stu_school)              # OLDBOY

print(Student.stu_school)               # OLDBOY
print(stu2_obj.stu_school)              # OLDBOY
print(stu3_obj.stu_school)              # OLDBOY

3.类中定义的函数主要是给对象使用的，而且是绑定给对象的，虽然所有对象指向的都是相同的功能，但是绑定到不同的对象就是不同的绑定方法，内存地址各不相同

# 类调用自己的函数属性必须严格按照函数的用法来
print(Student.tell_stu_info)        # <function Student.tell_stu_info at 0x00A58460>
print(Student.set_info)             # <function Student.set_info at 0x00A58418>

Student.tell_stu_info(stu1_obj)     # 学生信息：名字：egon 年龄：18 性别：male
Student.tell_stu_info(stu2_obj)     # 学生信息：名字：lili 年龄：19 性别：female
Student.tell_stu_info(stu3_obj)     # 学生信息：名字：jack 年龄：20 性别：male

Student.set_info(stu1_obj,'EGON',19,'MALE')
Student.tell_stu_info(stu1_obj)     # 学生信息：名字：EGON 年龄：19 性别：MALE


# 绑定方法的特殊之处在于：谁来调用绑定方法就会将谁当做第一个参数自动传入
print(Student.tell_stu_info)        # <function Student.tell_stu_info at 0x01948460>
print(stu1_obj.tell_stu_info)       # <bound method Student.tell_stu_info of <__main__.Student object at 0x0194B0B8>>
print(stu2_obj.tell_stu_info)       # <bound method Student.tell_stu_info of <__main__.Student object at 0x0194B070>>
print(stu3_obj.tell_stu_info)       # <bound method Student.tell_stu_info of <__main__.Student object at 0x0194B250>>

stu1_obj.tell_stu_info()  # tell_stu_info(stu1_obj)     # 学生信息：名字：egon 年龄：18 性别：male
stu2_obj.tell_stu_info()  # tell_stu_info(stu2_obj)     # 学生信息：名字：lili 年龄：19 性别：female
stu3_obj.tell_stu_info()  # tell_stu_info(stu3_obj)     # 学生信息：名字：jack 年龄：20 性别：male


stu1_obj.choose('python全栈开发')
print(stu1_obj.course)  
# 正在选课
# python全栈开发

stu2_obj.choose('linux运维')
print(stu2_obj.course)  
# 正在选课
# linux运维

stu3_obj.choose('高级架构师')
print(stu3_obj.course)  
# 正在选课
# 高级架构师

l1 = ['aa', 'bb', 'cc']     # l=list([1,2,3])
l2 = [111, 222, 333]        # l=list([1,2,3])
print(l1.append)            # <built-in method append of list object at 0x0114D048>
print(list.append)          # <method 'append' of 'list' objects>

l1.append('dd')
l2.append('dd')
print(l1)                   # ['aa', 'bb', 'cc', 'dd']
print(l2)                   # [111, 222, 333, 'dd']

l1 = ['aa', 'bb', 'cc']  # l=list([1,2,3])
l2 = [111, 222, 333]  # l=list([1,2,3])

list.append(l1, 'dd')
list.append(l2, 'dd')
print(l1)       # ['aa', 'bb', 'cc', 'dd']
print(l2)       # [111, 222, 333, 'dd']