Python语言的面向对象编程的介绍（附代码）

一、
#1 定义一个类，其中类名是学生
#2 学生具有的属性
#3 学生具有哪些行为
#4 具体化两个学生，实例化类型
class Student(object):
    name = " "
    age = 12
    weight = 50
    school = "wuhan university"
    def eat(self,orange):
        print("l love orange")
    def study(self):
        print("let me study!")
stu1 = Student()
stu2 = Student()
print(stu1)
print(stu2)
print(stu1.name)
print(stu1.age)
print(stu2.name)
print(stu2.age)

二、
#进一步优化：通过上面的程序我们发现他们最终输出的对象的属性一样，但是事实上他们是两个不同的学生，他们的名字，年龄并不相同，那么接下来需要做的就是给他们各自赋予各自的属性，利用类名.属性=某个值，和方法的调用一样也是类名.方法名
class Student(object):
    name = " "
    age = 12
    weight = 50
    school = "wuhan university"
    def eat(self,orange):
        print("l love orange")
    def study(self):
        print("let me study!")
stu1 = Student()
stu1.name="王"
stu1.age = 20

stu2 = Student()
stu2.name = "张"
stu2.age = 50
print(stu1)
print(stu1.name)
print(stu1.age)
print(stu2)
print(stu2.name)
三、
#进一步优化：通过第二个程序我们发现在定义对象的属性时我们还需要将所得属性命名在写一次，这样显然比价麻烦，于是有了更好的属性命名方法，我们可以使用初始化 
def __init__(self,、、、)，最后在命名属性的时候只需要在类名后面的括号中填写具体的属性值即可，大大较少了代码量。

class Student(object):
    def __init__(self,name,age,school):
        self.name = name
        self.age = age
        self.school = school
    def eat(self,orange):
        print("l love orange")
    def study(self):
        print("let me study!")
stu1 = Student("li",25,"scu")
stu2 = Student("sun",20,"wpu")
print(stu1)
print(stu2)
print(stu1.name)
print(stu1.school)
print(stu2.name)
print(stu2.school)

class Student(object):
    def __init__(self,name,age,school):
        self.name = name
        self.age = age
        self.school = school
    def eat(self,orange):
        print("l love orange")
    def study(self):
        print("let me study!")
    def intro(self):
        print("my name is{},{} years old".format(self.name,self.age))
stu1 = Student("li",25,"scu")
stu2 = Student("sun",20,"wpu")
print(stu1)
print(stu2)
print(stu1.name)
print(stu1.school)
print(stu2.name)
print(stu2.school)
intro1 = stu1.intro()
intro2 = stu2.intro()

class Student(object):
    def __init__(self,name,age,school):
        self.name = name
        self.age = age
        self.school = school
    def eat(self,orange):
        print("l love orange")
    def study(self):
        print("let me study!")
    def intro(self):
        print("my name is{},{} years old".format(self.name,self.age))
    def __str__(self):
        return "%s-%d"%(self.name,self.age)
stu1 = Student("li",25,"scu")
stu2 = Student("sun",20,"wpu")


print(stu1)