20.Python：with上下文管理

# 文件对象又称文件句柄

# with open("a.txt", mode="rt") as f1:
#    res = f1.read()
#    print(res)

with open("a.txt", mode="rt") as f1, open("b.txt", mode="rt") as f2:

    res1 = f1.read()
    res2 = f2.read()

    print(res1)
    print(res2)

"""
换行的写法：
with open("a.txt", mode="rt") as f1,\
     open("b.txt", mode="rt") as f2:
"""