class ClassName:pass

class MyCalss:"""A example class"""#文档字符串x = 'abc'#类属性def foo(self):#类属性foo,也是方法return 'myclass'

a = MyClass()   #实例化

class MyCalss:def __init__(self):#初始化print('init')a  = MyCalss()

class Person:def __init__(self):print(id(self))c = Person()    #会调用__init__
print('p={}'.format(id(c)))
#输出结果：
43079160
c=43079160

class Person:age = 7height = 175def __init__(self,name,age=23):self.name = nameself.age = agetom  = Person('tom')
jerry = Person('jerry',20)Person.age = 30
print(Person.age,tom.age,jerry.age)
print(Person.__dict__,tom.__dict__,jerry.__dict__,sep='\n')Person.height += 5
print(Person.__dict__,tom.__dict__,jerry.__dict__,sep='\n')tom.height = 176
print(Person.__dict__,tom.__dict__,jerry.__dict__,sep='\n')Person.weight = 65
print(Person.__dict__['weight'])
print(tom.__dict__['weight'])#KeyError

#增加类变量
def add_name(name,cls):cls.NAME = name #动态增加类属性#改进成装饰器(带参)
def add_name1(name):def wrapper(cls):cls.NAME = namereturn clsreturn wrapper@add_name1('tom')
class Person:AGE = 1print(Person.NAME)

class Person:def normal_method():print('nomal')def method(self):print("{}'s method ".format(self))@classmethoddef class_method(cls):print('class = {0.__name__}  {0}'.format(cls))cls.HEIGHT  =175@staticmethoddef static_method():print(Person.HEIGHT)#~~~类访问~~~
print(1,Person.normal_method())
# print(2,Person.method())#报错
print(3,Person.class_method())
print(4,Person.static_method())
#~~~实例访问~~~
tom = Person()
# print(5,tom.normal_method())#报错
print(6,tom.method())
print(7,tom.class_method())
print(8,tom.static_method())

一般来说，可以在内部自定义一个方法来访问私有变量。

#test1.py
from test2 import Person
from test3 import get_scoredef monkeypatch4Person():Person.get_score = get_scoreprint(Person().get_score())
monkeypatch4Person()print(Person().get_score())#输出如下：
{'English': 78, 'Chinese': 86, 'History': 82}    #打补丁前
{'name': 'Person', 'English': 88, 'Chinese': 90, 'History': 85}    #打补丁后

#test2.py
class Person:def get_score(self):ret = {'English':78,'Chinese':86,'History':82}return ret

#test3.py
def get_score(self):return dict(name=self.__class__.__name__,English=88,Chinese=90,History=85)

class Person:def __init__(self,chinese,english,history):self._chinese = chineseself._eng = englishself.__his = historydef gethis(self):return self.__hisdef sethis(self,value):self.__his = valuedef seteng(self,value):self._eng = value@propertydef chinese(self):return self._chinese@chinese.setterdef chinese(self,value):self._chinese = value@chinese.deleterdef chinese(self):# del self._chineseprint('del self._chinese')#x = property(getx, setx, delx, "I'm the 'x' property.")eng = property(lambda self:self._eng,seteng)student = Person(80,90,88)
print(student.chinese)#80
student.chinese = 100
print(student.chinese)#100
del student.chinese
print(student.eng)#90
student.eng =110
print(student.eng)#110

重写也就是覆盖的意思，即override。 

#1.其结构值得参考！
from random import randint
class RandomGenerator:def __init__(self,count=10,start=1,stop=100):self.count = countself.start = startself.stop = stopself.gen = self._generatr()def _generatr(self):while True:yield [randint(self.start,self.stop) for _ in range(self.count)]def gengerate(self,count):self.count = countreturn next(self.gen)rg = RandomGenerator()
lst = rg.gengerate(10)
print(lst)

#2
class Point:def __init__(self,x,y):self.x = xself.y = ydef __repr__(self):return  '{}:{}'.format(self.x,self.y)
lst1 = [Point(*v) for v in zip(rg.gengerate(10),rg.gengerate(10))]
print(lst1)
#输出如下：
[36:14, 84:20, 31:84, 68:82, 36:48, 87:67, 64:49, 8:15, 55:73, 90:75]

#3
class Car:def __init__(self,mark=None,color=None,price=None,speed=None):self._mark = markself._color = colorself._price = priceself._speed = speedclass CarInfo:def __init__(self):self.lst = []def addcar(self,car:Car):self.lst.append(car)def showcarinfo(self):return self.lst

#4
class Temperature:def __init__(self,t,unit='c'):self._c = Noneself._f = Noneself._k = Noneif unit == 'k':self._c = self.k2c(t)self._k = telif unit == 'f':self._c = self.f2c(t)self._f = telse:self._c = t@propertydef k(self):if self._k is None:self._k = self.c2k(self._c)return self._k@propertydef f(self):if self._f is None:self._f = self.c2f(self._c)return self._f@propertydef c(self):return self._c@classmethoddef c2f(cls,c):return c*9/5+32@classmethoddef f2c(cls,f):return (f-32)*5/9@classmethoddef c2k(cls,c):return c+273.15@classmethoddef k2c(cls,k):return k-273.15@classmethoddef f2k(cls,f):return cls.c2k(cls.f2c(f))@classmethoddef k2f(cls,k):return cls.c2f(cls.k2c(k))print(Temperature.c2f(40))
print(Temperature.c2k(40))
print(Temperature.f2c(104.0))
print(Temperature.f2k(104.0))
print(Temperature.k2c(313.5))
print(Temperature.k2f(313.5))t = Temperature(40)
print(t.c,t.f,t.k)t = Temperature(313.5,'k')
print(t.c,t.f,t.k)

#简单购物车
class Color:RED = 0BLUE = 1GREEN = 2BLACK = 3GOLDEN = 4OTHER = 100class Item:def __init__(self,**kwargs):self.__info = kwargsdef __repr__(self):return str(sorted(self.__info.items()))class Cart:def __init__(self):self.items = []def additem(self,item:Item):self.items.append(item)def gatallitems(self):return self.itemsmycart = Cart()
myphone = Item(mark='Iponhe',color=Color.GOLDEN,memory='64G')
mycart.additem(myphone)
mycar = Item(mark='BMW',color=Color.BLACK,memory='220/s')
mycart.additem(mycar)
print(mycart.gatallitems())