writing classes in python

__call__ (CLS, *args, **kwargs): # #执行Type的__call__方法, the CLS here is 　　#================================= Dependency Injection Case one ======================================class MyType (type): def __ Call__ (CLS, *args, **kwargs): # #执行Type的__call__方法, the CLS here is obj.__init__ (Foo ()) elif cls = = Foo2: obj.__init__ (Foo1 ()) return objclass Foo (metaclass=mytype): def __init__ (self, args): print (' ============ ') self.name = args

The first step: Define three Classes First: classAnimal:def __init__(self, name): Self.name=name#This means that if you inherit the class, you have to write your own talk method and throw an exception if you don't write it. defTalk (self):RaiseNotimplementederror ("subclass must implement abstract method")classCat (Animal):defTalk (self):return "meow!"classDog (Animal):defTalk (self):return "woof! woof!"Step Two: The first method to achieve polymor

Now I know there are two ways to do this:1 class inheritance Dict classes definedFor exampleClass A (dict): PassA = A ()a[' name '] = 122 Adding a custom class__setitem__ () __getitem__ () methodClass A:def __init__ (self, cfg={}):self.cfg = cfgdef __setitem__ (self, Key, value): self.cfg[key] = Valuedef __ge Titem__ (self, key): Return self.cfg[key]a = A () a[' B '] = 2print (a[' B '))Output:2[finished in 0.0s]This is to add a dictionary class object

are concentrated in the user layer, Internet applications, enterprise internal software, games, etc.Advantages: Solve the problem of poor scalability of the program, the modification of an object will be immediately reflected in the entire program system, such as LOL on a Hero attribute modification (years weakening has never been strengthened)Cons: Poor controllability, inability to predict program execution results, such as LOL per game resultsClasses and objectsThe concept of objectsObject i

1, static properties. @property. The function is to encapsulate the functions of a class into similar data attributes.class Student (object): School='szu' @property def printmassage (self): Print ('aaaa') S1=Student () s1.printmassage #aaaa2, the class method: Is the class object has the method, needs to use the decorator @classmethod to identify it as the class method, for the class method, the first parameter must be the class object, generally takes cls as the first param

first, the new old class of Python object-oriented 1) New Class (recommended): When defining a class, the class is followed by the base class (object) in parentheses. In python3.x, if the parent class is not specified, object is used as the base class by default, and in python2.x, if no parent class is specified, object is not used as the base class. 2) Legacy Class (classic Class): When you define a class, the class does not inherit the object class

Learning Points of knowledge:Classconstructor functionDestructorsPrivate methods, private propertiesclass variablesInstance variable1 #__*__ coding:utf-8 __*__2 __author__="david.z"3 4 classRole:5n = 123#class Variables6n_list=[]7Name ="I am the class name"8 def __init__(self,name,role,weapon,life_value=100,money=15000):9 #constructor FunctionTen #do some initialization of classes at instantiation One ASelf.name = Name#r1.name=nam

;> f.filter ([1], 2, 3]>>> s= Spamfilter () >>> s.init () >>> s.filter ([' SPAM ', ' SPAM ', ' egg ', ' name ', ' FF ')] [' egg ', ' name ', ' FF '] Inheritance, Super class >>> class Filter: def init (self): self.blockes=[] def Filter (self,sequence): return [x For x in sequence if x isn't in self.blocked] >>> class S (Filter): def init (self): self.blocked=[' s '] >>> f=filter () >>> f.init () >>> f.filter ([]) Multiple Super Class Methods in an inher

Ref_info.items () if Item[1]!=none]OUT_FILES=[ITEM[0] for item in Ref_info.items () if Item[1]==none]Spark_not_found=[f for F in Out_files if F.startswith ("Org.apache.spark.")]Spark_not_found.sort ()Hadoop_files=[f for F in Out_files if F.startswith ("Org.apache.hadoop.")]Hadoop_files.sort ()Other_files=list (Set (Out_files)-Set (Spark_not_found)-Set (Hadoop_files))Other_files.sort ()Show_files_with_lines (In_files, "spark source")Show_files (Spark_not_found, "Spark import name not file name")

Add attributes and generate objects dynamically in python classes. This article will solve the problem one by one through the following aspects: 1. Main Functions of the program 2. Implementation Process 3. Class Definition 4. Use the generator to dynamically update each object and return the object 5. Remove unnecessary characters Using strip 6. rematch matching strings 7. Use timestrptime to extract strin

will be thrown if it does not exist attributeerror GetAttr (A, ' B ', ' The property you are accessing does not exist ') SetAttr (object, name, value) sets the value of the object Name property to a new property if the property does not existDelattr (object, name) removes the established property if it is not thrown attributeerrorProperty () Setting properties by property X = Property (GetSize, SetSize, delsize) set an X attribute that can manipulate GetSize, setSize, Del

=new_name theSelf.area =New_area * $ def __str__(self):Panax Notoginseng return "the brand of the bed is:%s, the area is:%d"%(Self.name,self.area) - the defGet_area (self): + returnSelf.area A the defget_name (self): + returnSelf.name - $ $ #instantiation of -Fangzi = Home (130,"three bedroom and one living room","Tang Zhen Tang man yuan, Pudong New area, Shanghai city") - #class Information Printing the Print(Fangzi) - Wuyi theBed1 = Bed ("Simmons"