python--part4

十三、__del__的使用

有一个特殊的方法__del__，它在对象消逝的时候被调用。对象消

逝即对象不再被使用，它所占用的内存将返回给系统作它用

 

十四、class的使用

class person:

    count = 0

    def __init__(self,name,age):

        self.name=name

        self.age=age

        person.count+=1     #用计数的

        print'count :%d'%person.count  

        print'person %s has Initionalized'%self.name

    def tell(self):

        print 'Name is : %s,Age is :%d'%(self.name,self.age)    

class teacher(person):

    def __init__(self,name,age,salary):

        person.__init__(self, name, age)

        self.salary=salary

        print 'teacher %s has Initionalized'%self.name

    def tell(self):

        person.tell(self)

        print 'salary is : %d'%self.salary          #

class student(person):

    def __init__(self,name,age,marks):

        person.__init__(self, name, age)

        self.marks=marks

        print 'student %s has Initionalized'%self.name

    def tell(self):

        person.tell(self)

        print 'marks is : %d'%self.marks

 

t = teacher('chenlei',12,200)

s = student('wuxiao',10,300)

member=[t,s]           

    """将两个对象添加到数组中 """

for me in member:

    me.tell()

 

十五、python中的累加

  person.count+=1

 

十六、pythoon中读取本地文件

从指定的路径读取文件

f = file('D:\soft\README.txt')

# if no mode is specified, 'r'ead mode is assumed by default

while True:

    line = f.readline()

    if len(line) == 0: # 注意这里要判读文件时候为空的文件

        break

    print line,

    # Notice comma to avoid automatic newline added by Python

f.close() # close the file