一.约束
约束某各类
用于约束其派生类,保证其派生类中有send方法,不然执行可能会报错
约束其派生类,python中用类来实现,Java和C#中用接口或类来实现
(1) 对于Java/C#:
类:(java和C#是先编译后运行的,所以如果不满足条件,一开始就会报错,根本无法运行)
1 class Foo:
2 def f1(self):
3 pass #可认为抛出异常
4
5 抽象类:约束他的派生类必须实现他其中的抽象方法
6 abstact class Foo:
7 def f1(self): #此方法可以不用继承
8 pass
9
10 abstact def f2(self):
11 pass
12 class Bar:
13 def f2(self):
14 pass
1 abstact class Foo:
2 def f1(self): #此方法可以不用继承
3 pass
4
5 abstact def f2(self):
6 pass
7 class Bar:
8 def f2(self):
9 pass
1 interface Foo:
2 def f1(self,x1):pass
3
4 def f2(self,x1):pass
5
6 interface Bar:
7 def f3(self,x1):pass
8
9 def f4(self,x1):pass
10
11 class Aou(Foo,Bar):
12 def f1(self,x1):pass
13
14 def f2(self,x1):pass
15
16 def f3(self,x1):pass
17
18 def f4(self,x1):pass
(2)python中:
1 class BaseMessage:
2 def send(self):
3 '''
4 必须继承BaseMessage,然后其中必须编写send方法,用于完成具体的业务逻辑
5 '''
6 # raise Exception('...')
7 raise NotImplementedError('send方法必须被重写') #更专业 #NotImplementedError是没有实现的意思
8
9 class Email(BaseMessage):
10 def send(self):
11 pass #发送邮件
12
13 def f1(self):
14 pass
15
16 def f2(self):
17 pass
18
19 class Wechat(BaseMessage):
20 def send(self):
21 pass
22
23 def f3(self):
24 pass
25
26 class Messege(BaseMessage):
27 def send(self):
28 pass
29
30 def f4(self):
31 pass
32
33 def func(arg):
34 '''
35 报警通知
36 :param arg:
37 :return:
38 '''
39 arg.send()
1 from abc import ABCMeta,abstractmethod
2 class Base(metaclass=ABCMeta): #定义了一个抽象类
3 def f1(self):
4 print(123)
5
6 @abstractmethod
7 def f2(self): #定义了一个抽象方法
8 pass
9
10 class Foo(Base):
11 def f2(self):
12 print(666)
13
14 obj=Foo()
15 obj.f1()
16 obj.f2()
总结:
1.什么是接口,以及作用?
接口是一种数据类型,用于约束派生类中必须实现指定方法
python中不存在,在Java和C#中存在
2.python中用什么来约束
抽象方法,抽象类(编写上麻烦)
认为主动抛出异常
3.约束时抛出的异常是否可以用其他的
不专业:raise Exception('...')
专业:raise NotImplementedError('send方法必须被重写')
4.以后看代码时,揣摩写代码的人的心思
5.应用场景:
多个类,内部都必须有某各类或某个方法时,需要使用基类+异常进行约束
1 class Base:
2 def login(self):
3 raise NotImplementedError('...')
4
5 class Student(Base):
6 def login(self):
7 pass
8 def score(self):
9 pass
10
11 class Teather(Base):
12 def login(self):
13 pass
14
15 def exam(self):
16 pass
17
18 class Messaer(Base):
19 def login(self):
20 pass
21 def set(self):
22 pass
二.自定义异常
1 import os
2 def func(path,prev):
3 '''
4 去路径的文件中,找到前缀为prev的一行数据,获取数据并返回给调用者'
5 1000 成功
6 1001 文件不存在
7 1002 关键字为空
8 1003 未知错误
9 :param path:
10 :param prev:
11 :return:
12 '''
13 response ={'code':1000,'data':None}
14 try:
15 if not os.path.exists(path):
16 response['code'] = 1001
17 response['data'] = '文件不存在'
18 return response
19 if not prev:
20 response['code'] = 1002
21 response['data'] = '关键字为空'
22 return response
23 except Exception as e:
24 response['code']=1003
25 response['data']='未知错误'
26 return response
27 def func2():
28 return 8
29 def show():
30 v1=func()
31 v2=func2()
1 class ExistsError(Exception): #自定义异常类,自定义的异常类要继承Exception
2 pass
3 class KeyInvalidError(Exception):
4 pass
5 import os
6 def new_func(path,prev):
7 '''
8 去路径的文件中,找到前缀为prev的一行数据,获取数据并返回给调用者'
9 1000 成功
10 1001 文件不存在
11 1002 关键字为空
12 1003 未知错误
13 '''
14 response ={'code':1000,'data':None}
15 try: #目的就是为了让try中的代码简单明了
16 if not os.path.exists(path):
17 raise ExistsError
18 if not prev:
19 raise KeyInvalidError
20 except ExistsError as e:
21 response['code'] = 1001
22 response['data'] = '文件不存在'
23 except KeyInvalidError as e:
24 response['code'] = 1002
25 response['data'] = '关键字为空'
26 except Exception as e:
27 response['code']=1003
28 response['data']='未知错误'
29 return response
30 def func2():
31 return 8
32 def show():
33 v1=new_func()
34 v2=func2()
1 class MyException(Exception): #异常也是一个类
2 def __init__(self,code,msg):
3 self.code=code
4 self.msg=msg
5
6 try : #主动抛出异常
7 raise MyException(1000,'异常类型')
8
9 except MyException as e: #捕获异常
10 print(e.code,e.msg)
三. 加密(一些密码类的内容,如果不加密一但泄露,会造成严重的)
import hashlib #帮助加密的模块
obj=hashlib.md5(b'6khiy78g76tfmjyvf64')
# 写入要加加密的字节
obj.update('admin'.encode('utf-8'))
v=obj.hexdigest() #获取密文
print(v)
关键词:撞库 将常见的密文归纳总结,一个一个试
加盐:obj=hashlib.md5(b'6khiy78g76tfmjyvf64')
1 Hash objects have these methods:
2 - update(arg): Update the hash object with the bytes in arg. Repeated calls
3 are equivalent to a single call with the concatenation of all
4 the arguments.
5 - digest(): Return the digest of the bytes passed to the update() method
6 so far.
7 - hexdigest(): Like digest() except the digest is returned as a unicode
8 object of double length, containing only hexadecimal digits.
9 - copy(): Return a copy (clone) of the hash object. This can be used to
10 efficiently compute the digests of strings that share a common
11 initial substring.
1 import hashlib
2 mi=b'6khiy78g76tfmjyvf64'
3 def md5(ped):
4
5 obj=hashlib.md5(mi)
6
7 obj.update('admin'.encode('utf-8'))
8
9 return obj.hexdigest()
10
11 name=input('亲输入用户名')
12 pwd=input('亲输入用密码')
13
14 if name=='ninini' and md5(pwd)=='263930cf6ae488d074e32def60d973cc':
15 print('登录成功')
四.日志(logging)
为什么要有日志:
给开发人员看,用于排查错误
import logging
#路径或文件名
logger=logging.basicConfig(filename='log.log',
format='%(asctime)s - %(name)s - %(levelname)s -%(module)s: %(message)s',
datefmt='%Y-%m-%d %H:%M:%S %p',
level=10) #用于控制日志的错误级别
logging.debug('x1') #10 正常测试
logging.info('x2') #20 正常的信息
logging.warning('x3') #30 警告
logging.error('x4') #40 错误
logging.critical('x5') #50 立即解决的错误
logging.log(10,'log')
def func():
try:
a=a+1
except Exception as e:
print(e)
logging.error(str(e))
func()
日志错误处理:
import logging
#路径或文件名
logger=logging.basicConfig(filename='log.log',
format='%(asctime)s - %(name)s - %(levelname)s -%(module)s: %(message)s',
datefmt='%Y-%m-%d %H:%M:%S %p',
level=10) #用于控制日志的错误级别
logging.debug('x1') #10 正常测试
logging.info('x2') #20 正常的信息
logging.warning('x3') #30 警告
logging.error('x4') #40 错误
logging.critical('x5') #50 立即解决的错误
logging.log(10,'log')
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()