f = None
for i in range (5):
with open("data.txt", "w") as f:
if i > 2:
break
print f.closed
a) True
b) False
c) None
d) Error
f = None
for i in range (5):
with open("data.txt", "w") as f:
if i > 2:
break
print f.closed
a) True
b) False
c) None
d) Error
a)True,与open文件一起使用时,WITH语句可确保在with块退出时关闭文件对象。