python笔记：类

#!python
#filename objvar.py
class Robot:
    '''Represents a robot, with a name.'''

    #class variable
    population=0

    def __init__(self,name):
        '''Initializes the data.'''
        self.name=name
        print('Initializing {0}'.format(self.name))

        Robot.population+=1
        
    def __del__(self):
        ''' I am dying...'''
        print('{0} is being destroyed!'.format(self.name))
        Robot.population-=1

        if Robot.population==0:
            print('{0} was the last one.'.format(self.name))
        else:
            print('There are still {0:d} robots working.'.format(Robot.population))

    def sayHi(self):
        '''Creeting by the robot.

    Yeah, they can to that.'''
        print('Creeting, my masters call me {0}.'.format(self.name))

    def howMany():
        '''Prints the current population.'''
        print('We have {0:d} robots.'.format(Robot.population))
    howMany=staticmethod(howMany)

droid1=Robot('WYL-01')
droid1.sayHi()
Robot.howMany()


droid2=Robot('WYL-02')
droid2.sayHi()
Robot.howMany()

print('Destorying robot....')
del droid1
del droid2

Robot.howMany()

#!python
#filename inherit.py
class SchoolMember:
    '''Represents any school member.'''
    def __init__(self,name,age):
        self.name=name
        self.age=age
        print('Initialized SchoolMember:{0}'.format(self.name))
    def tell(self):
        '''Tell me details'''
        print('Name:"{0}" Age:"{1}"'.format(self.name,self.age),end=" ")

class Teacher(SchoolMember):
    '''Represents to a teacher.'''
    def __init__(self,name,age,salary):
        SchoolMember.__init__(self,name,age)
        self.salary=salary
        print('Initialized Teacher:{0}'.format(self.name))
    def tell(self):
        SchoolMember.tell(self)
        print('Salary:"{0}"'.format(self.salary))

class Student(SchoolMember):
    '''Represents to a student.'''
    def __init__(self,name,age,marks):
        SchoolMember.__init__(self,name,age)
        self.marks=marks
        print('Inintialized Student:{0}'.format(self.name))
    def tell(self):
        SchoolMember.tell(self)
        print('Marks:"{0:d}"'.format(self.marks))

t=Teacher('Mrs. Shrividya',40,3000)
s=Student('Swaroop',25,75)

print()#print a blank line

members=[t,s]
for member in members:
    member.tell()