f=open("yesterday","r",encoding="utf-8")  #文件句柄

 #文件内指针的操作

 print (f.tell())

 #f.read(5)

 print (f.readline())

 print (f.readline())

 print (f.readline())

 print (f.tell())

 f.seek(0)

 print (f.readline())

 print (f.encoding)#编码

 print (f.fileno())#文件号

 print (f.flush())#刷新

 import sys,time

 for i in range(50):

     sys.stdout.write("#")

     sys.stdout.flush()

     time.sleep(0.1)

 f=open("yesterday","r+",encoding="utf-8")  #读写

 #f=open("yesterday","w+",encoding="utf-8")  #写读