Python object-oriented,

Python object-oriented,
1. Object 1.1 Polymorphism

This means that the same operation can be performed on objects of different classes.

1.2 Encapsulation

Working details of hidden objects in the external world

1.3 inheritance

Create specialized class objects based on common classes

 

2. Class and type 2.1 create class

# Create class mycalss: z = 10086 # There is a special difference between class methods and common functions, they must have an additional first parameter name self # self, such as this, but because it represents the object itself, it is often called self def add (self, x, y): print (x + y) def getting (self): print ("Hello") def info (self, name, age): self. name = name self. age = ageobj = mycalss () obj. getting () obj. add (2, 3) obj.info ("Bob", "18") print (obj. name, obj. age) Output: Hello5Bob 18

2.2 privatization

Class mycalss: name = "Bob" # privatization method def _ inaccessible (self): print ("_ inaccessible cannot be accessed from outside") obj = mycalss () # access nameprint (obj. name) # You can modify nameobj. name = "Jack" print (obj. name) obj. _ inaccessible () Output: BobJackTraceback (most recent call last): File "c: \ Users \ jm \ Desktop \ PythonSpace \ Untitled-6.py", line 17, in <module> obj. _ inaccessible () AttributeError: 'mycalls' object has no attribute' _ inaccessible'

Class mycalss: name = "Bob" # privatization method currently _ inaccessible def _ inaccessible (self): print ("_ inaccessible") cannot be accessed from outside ") def accessible (self): self. _ inaccessible () # The method can internally access obj = mycalss () obj. accessible () Output :__ inaccessible

2.3 class attributes

You can use vertex (.) to access object attributes.

You can also use the following functions to access attributes:

Getattr (obj, name [, default]): hasattr (obj, name) of the object to be accessed: Check whether there is an attribute setattr (obj, name, value): Set an attribute. If the property does not exist, a new property delattr (obj, name) will be created: Delete the property setattr (obj, name, value): Set an attribute. If the property does not exist, a new property is created.

2.4 inheritance

Class Filter: def init (self): self. blocked = [] def filter (self, sequence): return [x for x in sequence if x not in self. blocked] class SPAMFilter (Filter): # SPAMFilter is a subclass of Filter (single inheritance) def init (self): # override the init method self. blocked = ["SPAM"] f = Filter () f. init () print (f. filter ([1, 2, 3]) s = SPAMFilter () s. init () print (s. filter (["SPAM", "SPAM", "eggs", "bacon", "SPAM"]) # filter "SPAM" output: [1, 2, 3] ['eggs', 'bacon']

# Multi-inheritance class class1 (object): def getting (self): print ("class1") class class2 (object): def getting2 (self): print ("class2 ") class class3 (class1, class2): passcl = class3 () cl. getting () cl. getting2 () Output: class1class2

2.5 Constructor

Class student (object): def _ init _ (self, name, age): self. name = name self. age = ages = student ("Bob", "18") print (s. name, s. age) Output: Bob 18