上下文管理my_open

import queue
import contextlib
q=queue.Queue()
li=[]
@contextlib.contextmanager
def my_open(file_path,val):
    f=open(file_path,mode=val,encoding='utf-8')
    try:
        yield f
    finally:
        f.close()
with my_open('ag.txt','w') as f1:
    print(f1.readline)