day27——面向对象编程

一：面向过程 与 面向对象

面向过程：

核心是‘过程’二字
过程的终极奥义：将程序流程化
过程是‘流水线’，用来分步骤解决问题的

面向对象：

核心是‘对象’二字
对象的终极奥义：将程序‘整合’
对象是‘容器’，用来盛放 数据 与 功能的

程序 = 数据 + 功能

二：实现方法

初级版

# 学生的数据
stu_name = 'xxq'
stu_age = 18
stu_gender = 'male'

# 学生的功能
def tell_stu_info():
    print(f'学生信息 - 名字：{stu_name} 年龄：{stu_age} 性别：{stu_gender}')

# 课程的数据
course_name = 'python'
course_period = '6month'
course_score = 10

# 课程的功能
def tell_course_info():
    print(f'课程信息 - 名称：{course_name} 周期：{course_period} 学分：{course_score}')


def set_info():
    global stu_name
    global stu_age
    global stu_gender

    stu_name = 'egon'
    stu_age = 80
    stu_gender = 'female'

    tell_stu_info()


set_info()

# 结果
学生信息 - 名字：egon 年龄：80 性别：female

进阶版

# 学生的功能
def tell_stu_info(stu_obj):
    print('学生信息 - 名字：%s 年龄：%s 性别：%s' % (
        stu_obj['stu_name'],
        stu_obj['stu_age'],
        stu_obj['stu_gender']
    ))


def set_info(stu_obj, x, y, z):
    stu_obj['stu_name'] = x
    stu_obj['stu_age'] = y
    stu_obj['stu_gender'] = z
    # stu_name = 'egon'
    # stu_age = 80
    # stu_gender = 'female'


stu_obj = {
    'stu_name': 'xxq',
    'stu_age': 18,
    'stu_gender': 'male',
    'tell_stu_info': tell_stu_info,
    'set_info': set_info,
}

print(stu_obj)
# 结果
{'stu_name': 'xxq', 'stu_age': 18, 'stu_gender': 'male', 'tell_stu_info': <function tell_stu_info at 0x00000216F95C9430>, 'set_info': <function set_info at 0x00000216F95C9790>}

高级版

# 学生的功能
def tell_stu_info(stu_obj):
    print('学生信息 - 名字：%s 年龄：%s 性别：%s' % (
        stu_obj['stu_name'],
        stu_obj['stu_age'],
        stu_obj['stu_gender']
    ))


def set_info(stu_obj, x, y, z):
    stu_obj['stu_name'] = x
    stu_obj['stu_age'] = y
    stu_obj['stu_gender'] = z
    # stu_name = 'egon'
    # stu_age = 80
    # stu_gender = 'female'


stu_obj = {
    'stu_school': 'oldboy',
    'stu_name': 'xxq',
    'stu_age': 18,
    'stu_gender': 'male',
    'tell_stu_info': tell_stu_info,
    'set_info': set_info,
}

stu1_obj = {
    'stu_school': 'oldboy',
    'stu_name': 'qwe',
    'stu_age': 18,
    'stu_gender': 'female',
    'tell_stu_info': tell_stu_info,
    'set_info': set_info,
}

print(stu_obj)

# 结果
{'stu_school': 'oldboy', 'stu_name': 'xxq', 'stu_age': 18, 'stu_gender': 'male', 'tell_stu_info': <function tell_stu_info at 0x0000023272F49430>, 'set_info': <function set_info at 0x0000023272F49790>}



# Python中的面向对象语法

### 类 是对象相似数据 与 功能的 集合体

### 所以，类中最常见的是变量 与 函数 的定义，但是 类体中 其实是可以包含任意其他代码的

#### 注意：类体代码 是在 类定义阶段就会立即执行的

```python
class Student:
    # 1.变量的定义
    stu_school = 'oldboy'

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

    def set_info(stu_obj, x, y, z):
        stu_obj['stu_name'] = x
        stu_obj['stu_age'] = y
        stu_obj['stu_gender'] = z

    # print('=======>')
    
# 属性访问的语法
# 1.访问数据属性
# 2.访问函数属性
print(Student.__dict__)        

{'__module__': '__main__', 'stu_school': 'oldboy', 'tell_stu_info': <function Student.tell_stu_info at 0x035B8418>, 'set_info': <function Student.set_info at 0x035B83D0>, '__dict__': <attribute '__dict__' of 'Student' objects>, '__weakref__': <attribute '__weakref__' of 'Student' objects>, '__doc__': None}

rint(Student.stu_school)     # oldboy

# 再调用类产生对象
stu1_obj = Student()
stu2_obj = Student()
stu3_obj = Student()

stu1_obj.__dict__['stu_name'] = 'eogn'
stu1_obj.__dict__['stu_age'] = 16
stu1_obj.__dict__['stu_gender'] = 'male'
print(stu1_obj.__dict__)  # {'stu_name': 'eogn', 'stu_age': 16, 'stu_gender': 'male'}

stu1_obj.stu_name = 'eogn'
stu1_obj.stu_age = 16
stu1_obj.stu_gender = 'male'
print(stu1_obj.__dict__)  # {'stu_name': 'eogn', 'stu_age': 16, 'stu_gender': 'male'}


# 一：属性查找

```python
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']