【脚本语言系列】关于Python基础知识面向对象编程，你需要知道的事

如何进行面向对象编程

类和对象

# -*- coding:utf-8 -*-
# create the class
class Animal:
def grow(self):
print "Animal grow..."
if __name__ == "__main__":
animal = Animal()
animal.grow()

Animal grow...

# -*- coding:utf-8 -*-
# display the class attribute&the instance attribute
class Animal:
price = 0

def __init__(self):
self.color = "black"
zone = "China"

if __name__ == "__main__":
print Animal.price
duck = Animal()
print duck.color
Animal.price = Animal.price + 10
print "duck's price:"+str(duck.price)
chick = Animal()
print "chick's price:" + str(chick.price)

0
black
duck's price:10
chick's price:10

属性和方法

# -*- coding:utf-8 -*-
# display the class attribute&the instance attribute
class Animal:
price = 0

def __init__(self):
self.__color = "black"
zone = "China"

if __name__ == "__main__":
duck = Animal()
print duck._Animal__color

# -*- coding:utf-8 -*-
# display the class attribute&the instance attribute
class Animal:
def __init__(self):
self.__color = "black"

class Duck(Animal):
pass

if __name__ == "__main__":
animal = Animal()
duck = Duck()
print Duck.__bases__
print duck.__dict__
print duck.__module__
print duck.__doc__

# -*- coding:utf-8 -*-
# display the class attribute&the instance attribute
class Animal:
def __init__(self):
self.__color = "black"

class Duck(Animal):
pass

if __name__ == "__main__":
animal = Animal()
duck = Duck()
print Duck.__bases__
print duck.__dict__
print duck.__module__
print duck.__doc__

# -*- coding:utf-8 -*-
# display the static mathod
class Animal:
price = 0

def __init__(self):
self.__color = "red"

def getColor(self):
print self.__color

@ staticmethod
def getPrice():
print Animal.price

def __getPrice():
Animal.price = Animal.price + 10
print Animal.price

count = staticmethod(__getPrice)

if __name__ == "__main__":
duck = Animal()
duck.getColor()
Animal.count()
chick = Animal()
chick.count()
chick.getPrice()

red
10
20
20

# -*- coding:utf-8 -*-
# display the class mathod
class Animal:
price = 0

def __init__(self):
self.__color = "red"

def getColor(self):
print self.__color

@ classmethod
def getPrice(self):
print Animal.price

def __getPrice(self):
Animal.price = self.price + 10
print self.price

count = classmethod(__getPrice)

if __name__ == "__main__":
duck = Animal()
duck.getColor()
Animal.count()
chick = Animal()
chick.count()
chick.getPrice()

# -*- coding:utf-8 -*-
# display the inside class
class Bus:
class Door:
def open(self):
print "open door"
class Wheel:
def run(self):
print "Bus run"

if __name__ == "__main__":
bus = Bus()
backDoor = Bus.Door()
frontDoor = Bus.Door()
backDoor.open()
frontDoor.open()
wheel = Bus.Wheel()
wheel.run()

# -*- coding:utf-8 -*-
# display the __init__ method
class Bus:
def __init__(self, color):
self.__color = color
print self.__color
def getColor(self):
print self.__color
def setColor(self, color):
self.__color = color
print self.__color
if __name__ == "__main__":
color = "red"
bus = Bus(color)
bus.getColor()
bus.setColor("blue")

red
red
blue

# -*- coding:utf-8 -*-
# display the __del__ method
class Bus:
def __init__(self, color):
self.__color = color
print self.__color

def __del__(self):
self.__color = ""
print "free..."

def grow(self):
print "grow..."

if __name__ == "__main__":
color = "red"
bus = Bus(color)
bus.grow()

red
free...
grow...

# -*- coding:utf-8 -*-
import gc
# display the garbage collection
class Bus:
def __init__(self, name, color):
self.__name = name
self.__color = color

def getColor(self):
return self.__color

def setColor(self, color):
self.__color = color

def getName(self):
return self.__name

def setColor(self, name):
self.__name = name

class BusShop:
def __init__(self):
self.buses = []

def addBus(self, bus):
bus.parent = self
self.buses.append(bus)

if __name__ == "__main__":
shop = BusShop()
shop.addBus(Bus("small", "red"))
shop.addBus(Bus("big", "yellow"))
print gc.get_referrers(shop)
del shop
print gc.collect()

[{'_Bus__color': 'red', 'parent': <__main__.BusShop instance at 0x000000000347C288>, '_Bus__name': 'small'}, {'_Bus__color': 'yellow', 'parent': <__main__.BusShop instance at 0x000000000347C288>, '_Bus__name': 'big'},
...
...
...
print gc.get_referrers(shop)\n    del shop\n    print gc.collect()'], '_oh': {}, 'Out': {}}]
41

# -*- coding:utf-8 -*-
# display the __new__ method
class Singleton(object):
__instance = None

def __init__(self):
pass

def __new__(cls, *args, **kwd):
if Singleton.__instance is None:
Singleton.__inistance = object.__new__(cls, *args, **kwd)
return Singleton.__instance

# -*- coding:utf-8 -*-
# display the __getattr__and__setattr__ method
class Bus(object):
def __init__(self, color = "red", price = 0):
self.__color = color
self.__price = price

def __getattribute__(self, name):
return object.__getattribute__(self, name)
def __setattr__(self, name, value):
self.__dict__[name] = value
if __name__ == "__main__":
bus = Bus("blue", 10)
print bus.__dict__.get("_Bus__color")
bus.__dict__["_Bus__price"] = 5
print bus.__dict__.get("_Bus__price")

blue
5

# -*- coding:utf-8 -*-
# display the __getitem__ method
class BusShop:
def __getitem__(self, i):
return self.buses[i]

if __name__ == "__main__":
shop = BusShop()
shop.buses = ["small", "big"]
print shop[1]
for item in shop:
print item,

big
small big

# -*- coding:utf-8 -*-
# display the __str__ method
class Bus:
"Bus class"
def __str__(self):
return self.__doc__

if __name__ == "__main__":
bus = Bus()
print str(bus)

Bus class

# -*- coding:utf-8 -*-
# display the __call__ method
class Bus:
class Aging:
def __call__(self):
print "aging..."
aging = Aging()

if __name__ == "__main__":
bus = Bus()
bus.aging()
Bus.aging()

aging...
aging...

# -*- coding:utf-8 -*-
# display the __call__ method
class Bus:
pass

def add(self):
print "aging..."

if __name__ == "__main__":
Bus.age = add
bus = Bus()
bus.age()

# -*- coding:utf-8 -*-
# display the __call__ method
class Bus:
def aging(self):
print "aging..."

def update():
print "aging......"

if __name__ == "__main__":
bus = Bus()
bus.aging()
bus.aging = update
bus.aging()

aging...
aging......

继承

# -*- coding:utf-8 -*-
# display the inherit
class Car:
def __init__(self, color):
self.color = color
print "Car's color: %s" %self.color

def aging(self):
print "aging ..."

class Bus(Car):
def __init__(self, color):
Car.__init__(self, color)
print "Bus's color: %s" %self.color

class Jeep(Car):
def __init__(self, color):
Car.__init__(self, color)
print "Jeep's color: %s" %self.color

def aging(self):
print "Jeep aging..."

if __name__ == "__main__":
bus = Bus("red")
bus.aging()
jeep = Jeep("yellow")
jeep.aging()

fruit's color: red
Bus's color: red
aging ...
fruit's color: yellow
Jeep's color: yellow
Jeep aging...

# -*- coding:utf-8 -*-
# display the inherit
class Car(object):
def __init__(self):
print "parent"

class Bus(Car):
def __init__(self):
super(Car, self).__init__()
print "child"

if __name__ == "__main__":
Bus()

child

# -*- coding:utf-8 -*-
# display the abstract class
def abstract():
raise NotImplementedError("abstract")

class Car(object):
def __init__(self):
if self.__class__ is Car:
abstract()
print "Car"

class Bus(Car):
def __init__(self):
Car.__init__(self)
print "Bus"

if __name__ == "__main__":
bus = Bus()
car = Car()

Car
Bus

----------------------------------------------------------------------

NotImplementedError                  Traceback (most recent call last)

<ipython-input-34-e90b06815f95> in <module>()
17 if __name__ == "__main__":
18     bus = Bus()
---> 19     car = Car()

<ipython-input-34-e90b06815f95> in __init__(self)
7     def __init__(self):
8         if self.__class__ is Car:
----> 9             abstract()
10         print "Car"
11

<ipython-input-34-e90b06815f95> in abstract()
2 # display the inherit
3 def abstract():
----> 4     raise NotImplementedError("abstract")
5
6 class Car(object):

NotImplementedError: abstract

# -*- coding:utf-8 -*-
# display the morphology
class Car:
def __init__(self, color=None):
self.color = color

class Bus(Car):
def __init__(self, color="red"):
Car.__init__(self, color)

class Jeep(Car):
def __init__(self, color = "yellow"):
Car.__init__(self, color)

class CarShop:
def sellCar(self, car):
if isinstance(car, Bus):
print "sell bus"
if isinstance(car, Jeep):
print "sell jeep"
if isinstance(car, Car):
print "sell car"
if __name__ == "__main__":
shop = CarShop()
bus = Bus("red")
jeep = Jeep("yellow")
shop.sellCar(bus)
shop.sellCar(jeep)

sell bus
sell car
sell jeep
sell car

# -*- coding:utf-8 -*-
# display the multi-inherit
class Car(object):
def __init__(self):
print "initialize Car"

def aging(self):
print "aging..."

class Suv(object):
def __init__(self, color="red"):
Car.__init__(self, color)

def jumping(self):
print "jumping..."

class Jeep(Car, Suv):
pass

if __name__ == "__main__":
jeep = Jeep()
jeep.aging()
jeep.jumping()

initialize Car
aging...
jumping...

# -*- coding:utf-8 -*-
# display the multi-inherit
class Car(object):
def __init__(self):
pass

class SpeedCar(Car):
def __init__(self):
print "initialize SpeedCar"

def speed(self):
print "speed..."

class JumpCar(Car):
def __init__(self):
print "initialize JumpCar"

def jump(self):
print "jump..."

class Bus(SpeedCar):
pass

class Jeep(JumpCar):
pass

# -*- coding:utf-8 -*-
# display the multi-inherit
class Car(object):
def __init__(self):
pass

class SpeedCar(object):
def __init__(self):
print "initialize SpeedCar"

def speed(self):
print "speed..."

class JumpCar(object):
def __init__(self):
print "initialize JumpCar"

def jump(self):
print "jump..."

class Bus(SpeedCar,Car):
pass

class Jeep(JumpCar,Car):
pass

# -*- coding:utf-8 -*-
# reload the operator
class Car(object):
def __init__(self,price=0):
self.price = price

def __add__(self, other):
return self.price + other.price

def __gt__(self, other):
if self.price > other.price:
flag = True
else:
flag = False
return flag

class Bus(Car):
pass

class Jeep(Car):
pass

if __name__== "__main__":
bus = Bus(3)
print "bus's price:", bus.price
jeep = Jeep(3)
print "jeep's price:", jeep.price
print jeep > bus
total = bus + jeep
print "total: ", total

bus's price: 3
jeep's price: 3
False
total:  6

# -*- coding:utf-8 -*-
import sys
# reload the operator
class Stream:
def __init__(self, file):
self.file = file

def __lshift__(self, obj):
self.file.write(str(obj))
return self

class Car(Stream):
def __init__(self, price = 0, file = None):
Stream.__init__(self, file)
self.price = price

class Bus(Car):
pass

class Jeep(Car):
pass

if __name__== "__main__":
bus = Bus(2, sys.stdout)
jeep = Jeep(3, sys.stdout)
endl = "\n"
bus << bus.price << endl
jeep << jeep.price << endl

2
3

什么是面向对象