python文件操作

#f = open("yesterday2.py",'r+',encoding="utf-8",) #文件句柄   读写
#f = open("yesterday2.py",'w+',encoding="utf-8",) #文件句柄pr   写读
#f = open("yesterday2.py",'a+',encoding="utf-8",) #文件句柄pr   追加
f = open("yesterday2.py",'rb') #文件句柄pr  二进制文件
print(f.readline())
print(f.readline())

print(f.readline())