Object-oriented, and the like objects

Object-oriented concepts
　　1, object-oriented programming --Object Oriented Programming, referred to as OOP, is a programming idea.
　　2, it is the object program as a basic unit. The program data and processing the data package to the object

• Advantages and disadvantages of
  advantages: ① good ② good flexibility and scalability, reusability ③ good shortcomings: ① ② increase the complexity of the program can not predict the results
• Use scenario
  for high scalability required procedures, usually directly to the user, e.g. qq, micro-Letter
• Process-oriented programming ideas
  core concern is the process, step by step process is the execution of advantages: logical, simplify complex issues, streamline
  Disadvantages: poor scalability, maintainability usage scenarios: low scalability requirements of the program, such as the kernel calculator
  Note:
  not all program objects must be oriented to analyze specific issues
• The concept of classes and objects
  • Class definition:
    either type, class, an abstract concept is a set of features and the same behavior with the same object
  • Definition of an object:
    a thing is a concrete existence, have their own characteristics and behavior of an object is a combination of characteristics and skills
  • Relationship classes and objects:
    class contains a series of objects, the object belongs to a class;
    in life is to have an object class and then there is the first in the program in order to have an object class, we kind of have to tell the computer;
    What features of the object behavior summed up what a conclusion:
    when using the object-oriented programming, the first step is the need to think what kind of objects, objects have what kind of features and behavior,
    which summed up the type of information required in accordance with
• How to create classes and objects
  • The definition of class

    name of class class: 
        content # class describes the attributes and skills 
        # description attribute with variable 
        # describe the behavior of a function 
    
    # class name written specification above all see the name known Italian names are big hump nomenclature   
    # Hump is the word capitalized large hump is the first letter capitalized, small hump is the first letter lowercase

  • Create Object

    Person class: 
        Pass 
    
    after # definition of a good class, you can create objects based on the Person class Person 
    p = Person ()

• Design attributes and search order
  • Properties design
    properties can be written in the class class property, is common to all objects 
    can also be written in an object object properties are unique (not the same) for each object
  • Find the order of attributes
    if there are the same attributes, first access the object if there is no access to classes in the class and object 
  • Exercise

    Exercise: Describe a class teacher needs to contain a public property (schools) and a unique attribute (name) 
    
    class Teacher: 
        School = "Oldboy" 
        
        DEF __init __ (Self, name, Age): 
        self.name = name 
        self.age = Age 
        
    Teacher = T1 () 
    t1.name = "Jack" 
    t1.age = 28

• Deletions attribute change search

  Increase property 
  object variable name. Attribute name = attribute value 
  
  to delete attribute 
  del Object Name Property Name del stu1.age 
  
  modify 
  objects. Attribute name = value of the new 
  
  view properties 
  print (Object .__ dict__) # access that object's properties  
  
  to access the object in that inside the class 
  print (Object .__ class__) # <class '__main　　 __. Teacher'>

• Initialization method init
  • Definition:
    a function for setting an initial value for the object's properties
  • Features:
    Features 1 :: when instantiating the object, it will automatically execute the init method
    Feature 2: automatically object as the first argument, the name of the parameter bit self, self can be another name, but it is not recommended to change
    the characteristics of 3 : You can not have a return value
  • Exercise

    # Exercise: Create a class with several properties to set the property to him by the initialization method 
    
    class Dog: 
        DEF __init __ (Self, kind, Color, Age): 
            self.kind = kind 
            self.color = Color 
            self.age Age = 
    
    d1 = Dog ( "two ha", "black and white",. 1) 
    D1 = Dog ( "Teddy", "brown", 2) 
    
    
    Note: this function does not have any return value / None predetermined so .... only. .　

  • Note: The
    essence of the object function is to integrate data and process the data together,
    so to get an object to get the data while the data to be processed and the processing function
• Binding and non-binding method method
  The default method in the case of class objects are bound method
  that is special because:
  when the function is called using the object will automatically pass the object itself, as the first argument
  when using the class name when he is to call a general function, there are several parameters have to pass a few parameters
  • Binding class method
    class binding method @classmethod to decorate
    special features:
    regardless of the call with a class or object will automatically incoming class itself, as the first argument
  • Non-binding approach
    . Or called a static method, that is, data that does not need to access the class does not need to access the object's data
    syntax: @staticmethod
  • How to determine the binding and to whom
    and when binding to the object: When the function logic required to access the data object
    when binding to the class: When the data logic function needs to access class