A review of basic knowledge--object-oriented programming

Tag: Blank relative to module reload includes att modifier character border

Before entering object-oriented programming, we want to make a collation of Python's common built-in functions, referring to the official website.

Common built-in functions

Chr (number)	Returns the ASCII code for a given number of characters
Ord (char)	Returns the ASCII value of an order character (a string of length 1 or a Unicode string)
All (iterable)	Returns true if all iterable elements are true, otherwise false
Any (iterable)	Returns true if any of the iterable elements are true, otherwise false
Callable (object)	Checks whether an object can be called
Dir ([Object])	Selectively list (most) attributes of a given object
Help ([Object])	Call the built-in Help system, or print help for a given object
Reload (module)	Reload into an already loaded module and return it
Repr (object)	Returns a String representing an object, typically used as an eval parameter
Eval (string[, globals[, locals])	To evaluate a string containing an expression
Input ([prompt])	Equivalent to eval (raw_input (Prompt)
Raw_input ([prompt])	Returns the data entered by the user as a string, optionally using the given prompt prompt
Str (object)	Returns a well-formatted string representing the object of the given objects
Type (object)	Returns the type of the given object

Object-Oriented Programming

Object-oriented is a programming method, which is relative to process-oriented, classify and encapsulate functions.

Initial knowledge of object-oriented concept
Concept	Description	Example
class	Some things in the real world are encapsulated in abstraction. Start with the keyword class, followed by the class name and colon.	class  person:        name = ' Lucy '        def setage (self,age):            self.age = Age
Object	A class defines an instance of an object that includes properties and methods. Objects are divided into class objects, instance objects
Class object	Once the class definition is complete, a global class object is created, and the properties and methods in the class can be accessed through the class object.	Person Class object
Instance Object	An instance object is an instantiation of a class that can instantiate multiple	p = person () instance object
Property	Describe what the object is or what it can do.
Class properties	The properties common to all instance objects of a class property, outside the class, can be defined or modified by class objects, within a class, only in class methods.	name = ' Lucy ' class property Person.country = ' China ' defined by class object
Instance Properties	The properties of an instance object that, when conflicting with a class property, mask the Class property.	P.country = ' China ' is defined by an instance object
Private properties	Starts with a double underscore and cannot be accessed directly outside of the class	__name = ' Lucy '
Function	Code blocks for specific functions for easy reuse	def setage (age): return age
Method	Method is the same as function function, written in the class, with the object in conjunction with	def setage (self,age): Self.age = Age
Class method	Methods with @classmethod modifiers and must have a CLS parameter, which can be accessed through instance objects and class objects	@classmethod def setage (cls,age): Cls.age = Age
Instance method	Methods with self, accessible only through instance objects	def setage (self,age): Self.age = Age
Static methods	Methods with @staticmethod modifiers that can only be accessed through class objects	@staticmethod def setage (age): return age

Common built-in methods

Built-in methods for classes
Built-in Method name	Description
__init__ (self,...)	Initializes an object that is called when a new object is created
__del__ (self)	Frees the object to be called before the object is deleted
__new__ (CLS,*ARGS,**KWD)	The build action of the instance
__str__ (self)	Called when the print statement is used
__call__ (Self,*args)	To call an instance object as a function
__GETATTR__ (S,name)	Gets the value of the property
__SETATTR__ (S,name,value)	Set the value of a property
__DELATTR__ (S,name)	Delete the value of an attribute

A review of basic knowledge--object-oriented programming