python introspection mechanism

python introspection is through a mechanism of the internal structure of the object

the Person class: 
    "" " 
    person 
    " "" 
    name = "the User" 

class Student (the Person): 
    DEF __init __ (Self, scool_name): 
        self.scool_name = scool_name 

IF __name__ == "__main__": 
    the User = Student ( "Mu class network ") 

    # __dict__ through query properties 
    print (user .__ dict__) # here does not find the name of the property to the Person, because it belongs to the class attribute of Person, not belonging to the object attribute 
    user .__ dict __ [" school_addr " ] =" Beijing " 
    Print (user.school_addr) 
    Print (the Person .__ dict__) 
    Print (user.name) 
    Print (dir (the User)) # will list all the properties of objects, only the attribute name, not the property value

 

You can return an object in python __dict__ and dir () properties, except that:

• __dict__ is a property of the object, and dir () is a built-in method;
• __dict__ return property name and value of an object, i.e. dict type, dir () Returns a property name of the List ;
• Each object has not __dict__, and dir () are functions for objects of various types, such as module, type, class, object;
• _dict__ object returns only writable property (writable attributes), and dir () Returns all relevant (relavent) properties, and for different types of objects, a different effect .