Python Abstraction and exception handling

#面向对象: polymorphism, encapsulation, inheritance
#1 polymorphism: It means that even if you don't know what type of object the variable refers to, you can manipulate it, and it will behave differently depending on his type.
#多态和方法

From randomImport Choice
x = Choice ([' Hello world ', [' 1 ',' 1 ',' 1 ',' 2 ',' 3 '])
Print (x)
Print (X.count (' 1 '))#1出现的次数 do not need to detect the type just need to know conut this method
#多态的多种形式: + operations function on strings, numbers

#2 encapsulation hides excess information from other areas in the global scope
#3 inheritance: Do not want code to reuse the original code
#4 class
#创建类
_metaclass_=Type
Class Person:
 Def setname (Self,name):
 Self.name = Name
 Def getname (Self):
 ReturnSelf.name
 def greet (Self):
 Print"Hello I am%s"%Self.name)
#调用类
Foo = person ()
Bar = person ()
Foo.setname ("1234567")
Bar.setname ("7891213")
Foo.greet ()
Bar.greet ()
Print (Foo.name,bar.name)
#-------------------------Output----------------------------------#
"""
C:\python3.7\python.exe d:/python-test/qiubai/qiubai/test6.py
Hello World
0
Hello I am 1234567
Hello I am 7891213
1234567 7891213
"""

#特性, Functions, methods
Class class:
 Def method (Self):
 Print"I am Self")
Def fuction ():
 Print"I don ' t ...")

obj = Class ()
Obj.method ()
Obj.method = fuction# attribute is bound to a normal function
Obj.method ()

Test = Obj.method#test变量引用绑定方法上
Test ()

#-------------------------Output----------------------------------#
"""
I am Self
I don ' t ...
I don ' t.
"""

#私有特性: To make the feature and method private (outside inaccessible), simply double-underline the name
#指定超类
Class Filter:
 DEF init (Self):
 Self.blocked=[]
 DEF filter (Self,test):
 return [xFor XIn testIf XNot inSelf.blocked]
 Def _test (Self):
 Print"I am Private")
Class Childfilter (Filter):#指定超类 Childfilter as a subclass of filter
 DEF init (Self):
 Print"I am the subclass is overriding the parent class method")
 self.blocked=[' As ']
f = Filter ()
F.init ()
Print (F.filter ([1,2,3]))

F1 = Childfilter ()
F1.init ()
Print (F1.filter ([1,23,56]))

#-------------------------Output----------------------------------#
"""
C:\python3.7\python.exe d:/python-test/qiubai/qiubai/test6.py
[1, 2, 3]
I'm a subclass. Overriding the parent class method
[1, 23, 56]
"""


#捕获异常
Try
x =5
y =0
 Print (x/y)
ExceptZerodivisionerror:
 Print"Denominator cannot be 0")
#-------------------------Output----------------------------------#
"""
C:\python3.7\python.exe d:/python-test/qiubai/qiubai/test6.py
The denominator cannot be 0
"""

# Raise
Class Muffledcalculator:
muffed =False
Def Calc (SELF,EXPR):
 Try
 Returneval (expr)
 ExceptZerodivisionerror:
 IfSelf.muffed:
 Print"Division is zero by illegal")
 Else
 Raise#
Cal = Muffledcalculator ()
Print (Cal.calc (' 10/2 '))
cal.muffed =True#打开屏蔽机制
Print"Hehehe-->", Cal.calc (' 10/0 '))
#-------------------------Output----------------------------------#
"""
C:\python3.7\python.exe d:/python-test/qiubai/qiubai/test6.py
The denominator cannot be 0
5.0
Division is zero by illegal
Hehehe--> None
"""

#用一个块捕捉两个异常
Try
x =Input"Input your first num:")
y =Input"Input YOUR second num:")
 Print (x/y)
ExceptZerodivisionerror,TypeError,Nameerror). E:
 Print"Your Num were Bug")
 Print (e)


While True:
 Try
x =intInput"Input your first num:"))
y=intInput"Input YOUR second num:"))
Value = x/y
 Print (value)
 ExceptEXCEPTION.E:
 Print"Exception", E)
 Print"Try Again")
 Else
 Break


"""
#-------------------------Output----------------------------------#
C:\python3.7\python.exe d:/python-test/qiubai/qiubai/test6.py
Input your first num:10input your second num:33.3333333333333335c:\python3.7\python.exe d:/python-test/qiubai/qiubai/ Test6.pyinput your first num:10input your second num:0traceback (most recent call last): File "D:/python-test/qiubai/qiuba i/test6.py ", line 145, in <module> value = X/yzerodivisionerror:division by zeroduring handling of the above except Ion, another exception Occurred:traceback (most recent): File ' d:/python-test/qiubai/qiubai/test6.py ', line 147 , in <module> except Exception.e:attributeerror:type object ' Exception ' have no attribute ' E ' "" "while true:try:x = Int (Input ("Input your first num:")) y= int (input ("Input YOUR second num:")) value = x/y print (value) except:print ("Try A Gain ") Else: #只有程序没有异常情况才会退出 Whenever an error occurs, the program constantly re-asks for the input break" "" #------------------------- Output----------------------------------#C: \python3.7\python.exe d:/python-test/qiubai/qiubai/test6.pyinput your First num:10input YOUR second num:0try againinput your first num:10input your second num:33.3333333333333335 "" #Finally: x = nonetry:x = x/0finally: #通常用于关闭文件或网络套接字 print (' Clean up ... ') del x #程序崩溃之前 For x variable cleanup "" "C:\python3.7\python.exe d:/python-test/qiubai/qiubai/test6.pyclean up .... Traceback (most recent): File "d:/python-test/qiubai/qiubai/test6.py", line 203, in <module> x = X/0type error:unsupported operand type (s) for/: ' Nonetype ' and ' int ' "" "

Python abstraction and exception handling