With a new recovery (home trip)

Binding

# Appreciated binding method 
DEF Fuc (): Pass 
Print (Fuc) 

class Foo:
     DEF Fuc (Self):
         Print ( ' FUNC ' ) 
F1 = Foo ()
 Print (f1.fuc)
 Print (Foo.fuc)

We can be found via their memory address, binding on the objects in the class. That is when the object is a method relying on the type of the object is equivalent to calling the method, the method is passed a value obtained class then return. When calling this object is bound to class together.

combination

It refers, in one class to another class of the object as a data property called composite class

Real columns: we can use to calculate a combined ring area to understand this concept.

from Math Import PI 

class Circle:
     '' ' 
    defines a circular class; 
    providing calculate the area (area) and a method circumference (Perimeter) a 
    ' '' 
    DEF  the __init__ (Self, RADIUS): 
        self.radius = RADIUS 

    DEF Area ( Self):
          return PI * * self.radius self.radius 

    DEF Perimeter (Self):
         return 2 * PI * self.radius 


circle = circle (10) # instantiate a circle 
Area1 = circle.area () # calculates circular area 
per1 circle.perimeter = () # calculates the circumferential length 
print(Area1, PER1) # print area and perimeter of circle 

class Ring:
     '' ' 
    defines a ring class 
    provides a method area and perimeter ring 
    ' '' 
    DEF  the __init__ (Self, radius_outside, radius_inside): 
        self.outsid_circle = Circle (radius_outside) 
        self.inside_circle = Circle (radius_inside) 

    DEF Area (Self):
         return self.outsid_circle.area () - self.inside_circle.area () 

    DEF Perimeter (Self):
         return   self.outsid_circle.perimeter () + self.inside_circle.perimeter () 


ring = ring (10,5) # instantiate an annular
Print (ring.perimeter ()) # calculation annular perimeter 
Print (ring.area ()) # calculating annular area

Popular, that is, when the interaction between a plurality of classes. Attribute value to make a further object of the object class.