day01-文件操作

#进度条
import sys,time
i=0
while i<=100:
    sys.stdout.write(‘*‘)
    sys.stdout.flush()#直接刷到内存
    time.sleep(1)
    i+=1

with open(‘song‘,‘r+‘) as f:
    f.readline()
    a=f.tell()
    f.readline()
    b=f.tell()
    f.readline()
    f.seek(a)#若后面加入f.readline()，不管seek到哪里，f.write都在文件末尾添加。否则在seek的位置覆盖添加
    f.write(‘this is added by fwrite\n‘)

#二进制读写
with open(‘song_write_wb‘,‘wb‘) as f:
    f.seek(10)
    f.write(‘this is added by fwrite\n‘.encode(encoding=‘utf-8‘))