面向对象的约束,加密,异常处理,日志文件

1,约束

class  BaseMessage(object):
    def send(self,x1):

        raise NotImplementedError(".send() 必须被从新写入.")

class   Email(BaseMessage):
    def  send(self,x1):

#必须继承BaseMessage,然后其中必须编写send方法.用于完成具体业务逻辑

        pass

obj = Email()
obj.send()


#2抽象类和抽象方法.
from abc import ABCMeta, abstractclassmethod

class Base(metaclass=ABCMeta):#这是一个抽象类
    def __init__(self, name, age):
        self.name = name
        self.age = age
        print()
    def func(self):
        print("In prosperity our friends know us; in adversity we know our friends.")

    @abstractclassmethod#抽象方法
    def func2(cls):
        pass

class  Fpp(Base):

    def func2(cls):
        print(666)

obj = Fpp(1,2)
obj.func()
3.如何自定义异常

class MyException(Exception):
    def __init__(self, code, msg):
        self.code = code
        self.msg = msg
try:
    raise MyException(100, "基本操作之-操作异常")

except KeyError as obj:
    print(obj, 1111)
except MyException as obj:
    print(obj, 2222)
except Exception as obj:
    print(obj, 3333)
#(100, '基本操作之-操作异常') 2222

3.加密
import  hashlib

Salt = b"12313213asdf"

def md5(pwd):
    #实例化对象
    obj = hashlib.md5(Salt)
    #写入要加密的字节 必须进行编码获得字节,文字不行

    obj.update(pwd.encode("utf-8"))
    #获取密文7883ad16b4e4565434d6fce3f62c951e
    return obj.hexdigest()
print(md5("find"))

user = input("请输入用户名:")
pwd = input("请输入密码:")
if user == "oldboys" and md5(pwd) == "7883ad16b4e4565434d6fce3f62c951e":
    print("login success")
else:
    print("fail")
#请输入用户名:oldboys
#请输入密码:find
# success

import  logging
logger = logging.basicConfig(filename='xxxxxxx.txt',
                             format='%(asctime)s - %(name)s - %(levelname)s -%(module)s:  %(message)s',
                             datefmt='%Y-%m-%d %H:%M:%S',
                             level=30)

# logging.debug('x1') # 10
# logging.info('x2')  # 20
# logging.warning('x3') # 30
# logging.error('x4')    # 40
# logging.critical('x5') # 50
# logging.log(10,'x6')


import traceback

def func():
    try:
        a = a +1
    except Exception as e:
        # 获取当前错误的堆栈信息
        msg = traceback.format_exc()
        logging.error(msg)
func()