今日作业
'''
0、课堂代码理解,并敲两遍以上 (技术的牛逼是靠量的积累)
1、定义MySQL类(参考答案:http://www.cnblogs.com/linhaifeng/articles/7341177.html#_label5)
1.对象有id、host、port三个属性
2.定义工具create_id,在实例化时为每个对象随机生成id,保证id唯一
3.提供两种实例化方式,方式一:用户传入host和port 方式二:从配置文件中读取host和port进行实例化
4.为对象定制方法,save和get_obj_by_id,save能自动将对象序列化到文件中,文件路径为配置文件中DB_PATH,文件名为id号,保存之前验证对象是否已经存在,若存在则抛出异常,;get_obj_by_id方法用来从文件中反序列化出对象
import os
import pickle
import random
import settings
class MySQL:
def __init__(self,host,port):
self.id=self.create_id()
self.hos=host
self.port=port
@staticmethod
def create_id():
return str(random.random())
def save(self):
if not self.is_exists:
raise TypeError('文件不存在')
file_path=r'%s%s%s' %(settings.DB_PATH,os.sep,self.id)
pickle.dump(self,open(file_path,'wb'))
@property
def is_exists(self):
tag=True
files=os.listdir(settings.DB_PATH)
for file in files:
file_abspath=r'%s%s%s' %(settings.DB_PATH,os.sep,file)
obj=pickle.load(open(file_abspath,'rb'))
if self.host== obj.host and self.port == obj.port:
tag=False
break
return tag
@staticmethod
def get_obj_by_id(id):
DB_PATH=os.path.join(os.path.dirname(__file__),str(id))
res=pickle.load(open(DB_PATH,'rb'))
return res
@classmethod
def from_conf(cls):
print(cls)
return cls(settings.HOST,settings.PORT)
conn=MySQL.from_conf()
conn.save()
2、定义一个类:圆形,该类有半径,周长,面积等属性,将半径隐藏起来,将周长与面积开放
import math
class Circle:
def __init__(self,r,):
self.__r=r
def A(self):
print(*math.pi*self.__r**2)
def P(self):
print(2*math.pi*self.__r*)
3、使用abc模块定义一个phone抽象类 并编写一个具体的实现类
import abc
class Phone(metaclass=abc.ABCMeta):
@abc.abstractmethod
def city(self):
pass
@abc.abstractmethod
def country(self):
pass
class Myphone(Phone):
def city(self):
pass
def country(self):
pass
my=Country()
4、着手编写选课系统作业:http://www.cnblogs.com/linhaifeng/articles/6182264.html#_label15
'''