chapter14-object-orientied-python

# simple python objects
class PartyAnimal: # making a PartyAnimal object # class is a tempalte (dog)
   x=0 # each PartyAnimal object has a bit of data
   def party(self): # each PartyAnimal object has a bit of code # party() is a method or message like bark(), capability of a class
       self.x = self.x + 1
       print "So far", self.x
an = PartyAnimal() # a is an object, which contain data (x 0) and code ( party() )
# an is an object or instance, a particular instance of a class - Lassie
an.party() # tell the object to run the party() code, = PartyAnimal.party(a); So far 1
an.party() # So far 2
an.party() # So far 3
# 'self' is a formal argument that refers to the object itself
  self.x is saying "x within self"
  in this case, self is alias of object an
  
dir() commend lists capabilities/methods # party(),x
type()   # instance

# object lifecycle
class .... :
   x=0
   def_init_(self):
       print"I am constructed" # self an once appreas, execute this # normal

   def party(self):
   :
   :

   def_def_(self):
       print"I am destructed", self.x   # rare

class PartyAnimal:
    x=0
    name = " "
    def_init_(self,nam):  # nam is the first parameter
        self.name = nam
        print self.name, "constructed"
    def party(self):
        self.x = self.x +1
        print self.name, "party count", self.x
s = PartyAnimal("Sally")
----------------------------------------------------------------------------
print(ord(‘H’) ->72, print (ord(‘e’))-> 101, print(ord(‘\n’))->10
ASCII, UTF-8 (Bytes), X=a’bcd’, type(x)->byte : In python3, all strings are Unicode, x=u’你好’, type(x)->str
Class(string), method/message(string.upper), field/attribute, object/instance
class PartyAnimal:
X=0
    Name=’’
def _init_(self,z):
  self.name=z
  print(‘self.name, “constructed”)
  
def party(self):
  self.x=self.x+1
  print(self.name, “party count”, self.x)
  
#def _del_(self):
#print (‘I am destructed’,self.x)

class FootballFan(PartyAnimal):  # Objective inheritance
points=0
def touchdown(self):
  self.points=self.points+7
  self.party()
print(self.name, “points”, self.points)

an=PartyAnimal()
s=PartyAnimal(‘Sally’)
s.party()
j=PartyAnimal(‘Jim’)
j.party()
j=FootballFan(‘Jim’)
j.party()
j.touchdown()
an.party()
an.party()
an.party()
an=42

print (“Type”,’type(an))
print(“Dir”, dir(an))
print(‘an contains’,an)