[Python知识库]类与对象[一]（Python）

本章我们来关注一下Python中的类与对象：

1.最基本的类结构

class Cdict:

    def getkeys(self,dicts):
        keys=[]
        for k in dicts:
            keys.append(k)
        return keys

    def getvals(self,dicts):
        vals=[]
        for k in dicts:
            vals.append(dicts[k])
        return vals

dicts={'name':'user1','age':20}

#从类中实例化对象
obj=Cdict

r=obj.getkeys(obj,dicts)
print(r)

r2=obj.getvals(obj,dicts)
print(r2)

2.默认参数

class Person:
    def _init_(self,name='user1'):
        self.name=name
        self.age=20

    def say(self):
        print(self.name,self.age)

obj=Person()
obj.say()

3.默认属性

def Person:
    def _init_(self,name):
        self.name=name
        self.age=20

    def say(self):
        print(self.name,self.age)

obj=Person('user1')
obj.say()

4.类中方法的分类

class Cdict:
    def _init_(sellf,dicts):
        self.dicts=dicts
        self.keys=[]
        self.vals=[]

    def getkeys(self):
        self.key=[]
        for k in self.dicts:
            self.dicts.append(k)
        return self.keys

    def getvals(self):
        self.vals=[]
        for k in self.dicts:
            self.vals.append(dicts[k])
        return self.vals

    def sum(self,i,j):
        return i+j

dicts={'name':'user1','age':20}

# 从类中实例化对象
obj=Cdict(dicts)

s=obj.sum(1,3)
print(s)

5.一个类使用另一个类

class Person:
	def __init__(self,name):
		self.name=name

	def say(self):
		return f'my name is {self.name}'

class Sub:
	def __init__(self,age):
		self.age=age

	def eat(self):
		x=Person('user1')
		z=x.say()

y=Sub(20)
y.eat()

6.类继承

class Person:
	def __init__(self,name='user1'):
		self.name=name
		self.age=20

	def say(self):
		print(self.name,self.age)

class Sub(Person):
	pass

obj=Sub()
obj.say()

7.类继承重载

class Person:
    def _init_(self,name):
        self.name=name

    def say(self):
        print(self.name)

class Sub(Person):
    def _init_(self,name,age):
        super()._init_(name)
        self.age=age

    def say(self):
        print(self.name,self.age)

obj=Sub('user1',20)
obj.say()

8.将实例用作属性

class Person:
	def __init__(self,name):
		self.name=name

	def say(self):
		return f'my name is {self.name}'

class Sub:
	def __init__(self,age):
		self.age=age
		self.per=Person('user1')


y=Sub(20)
print(y.per.say())

9.最后我们来一个完整的处理字典类Cdict

class Cdict:

	def __init__(self,dicts):
		self.keys=[]
		self.vals=[]
		self.dicts=dicts

	def getkeys(self):
		self.keys=[]

		for k in self.dicts:
			self.keys.append(k)	
		return self.keys

	def getvals(self):
		for k in self.dicts:
			self.vals.append(self.dicts[k])
		return self.vals

dicts={'name':'user1','age':20}

obj=Cdict(dicts)

keys=obj.getkeys()
print(keys)

vals=obj.getvals()
print(vals)

?可供初学者参考，我们下期再见！