[Python learning journey] --- Packaging and reflection (knowledge of class, object-oriented three characteristics: inheritance - polymorphism - Package)

The first layer encapsulating #: define a class 
# encapsulating the second layer: distinguish between inside and outside, some properties can only be used internally, not externally 


class the Name: 

    __A = 'you are a pig' # variable encapsulation A 
    DEF the __init __ (Self, name): 
        Self. name = name 

    DEF get_name (Self): 
        Print ( 'my name S%'% self.name) 


N1 = the name ( 'Chen Yuxia') 
Print (the name .__ dict__) # View class attributes dictionary 
print (n1._Name__a) # can this way call __a, there is no real package 

# genuine package: distinction between inside and outside, to provide users with an interface to access a function call, the internal logic to achieve, can not be known outside of 
class Room: 
    DEF __init __ (Self, name, Leng, width): 
        self.name name = 
        Self .__ = Leng Leng 
        Self .__ width = width 
    DEF GET (Self): # interface function, let's call the hidden attribute external 
        return Leng * Self Self .__ .__ width 

r1 = Room ( 'toilet' , 100,50) 
Print (r1.get ()) # external function by calling get


#Results of the:

{'__module__': '__main__', '_Name__a': '你是猪', '__init__': <function Name.__init__ at 0x00000232CEB08EA0>, 'get_name': <function Name.get_name at 0x00000232CEB08E18>, '__dict__': <attribute '__dict__' of 'Name' objects>, '__weakref__': <attribute '__weakref__' of 'Name' objects>, '__doc__': None}
你是猪
5000

# Detection program has its own function 
class Room: 
    DEF __init __ (Self, name, Leng, width): 
        self.name name = 
        Self .__ = Leng Leng 
        Self .__ width = width 
    DEF GET (Self): # interface functions, let's external call hidden attribute 
        return Leng Self .__ * Self .__ width 

r1 = Room ( 'WC', 100,50) 

Print (the hasattr (r1, 'name')) example # r1 detects whether there is the attribute name 
print (getattr (r1, 'name')) # Get the value of the instance attribute 
setattr (r1, 'name', ' bedroom') # instance attribute modification value 
Print (r1.name) 
delattr (R1, 'name') delete the value of the instance attribute # 
Print (R1 .__ dict__ magic) 

# hasattr benefits of using 
class the FTP: 
    DEF the __init __ (Self, addr): 
        Print ( "connecting to the server S%" addr%) 
        self.addr addr = 

F1 = the FTP ( '1.1.1.1')
if hasattr (FTP, 'get' ): # FTP determines whether there is a get function 
    a = getattr (FTP, 'get ') # available is acquired function address 
    a () # Run function 
the else: 
    Print ( "perform additional logic" ) 


# The results:

  True
  toilet
  bedroom
 { '_Room__leng': 100, ' _Room__width': 50}
 connecting to the server 1.1.1.1
 perform other logic