为什么无法通过 try-except 处理"io.UnsupportedOperation"错误

Question

运行以下代码会引起io.unsupportedeperation错误，因为该文件以"写"模式打开 -

with open("hi.txt", "w") as f:
    print(f.read())

输出是 -

io.UnsupportedOperation: not readable

因此，我们可以通过这样做来掩盖这一点 -

try:
    with open("hi.txt", "w") as f:
        print(f.read())
except io.UnsupportedOperation:
    print("Please give the file read permission")

输出 -

NameError: name 'io' is not defined

甚至删除" IO"。吐出相同的错误 -

try:
    with open("hi.txt", "w") as f:
        print(f.read())
except UnsupportedOperation:
    print("Please give the file read permission")

输出 -

NameError: name 'UnsupportedOperation' is not defined

为什么不起作用？" io.unsupporteDoperation"不是错误吗？

Answer 1

io.unsupportederror在模块IO中找到。因此，在我们使用它之前，我们需要导入IO

import io

然后，当我们在尝试中测试错误时，我们可以使用io.unsupportederror。这给了我们：

import io
try:
    with open("hi.txt", "w") as f:
        print(f.read())
except io.UnsupportedOperation as e:
    print(e)

或仅使用IO模块检查此特定错误。

from io import UnsupportedError
try:
    with open("hi.txt", "w") as f:
        print(f.read())
except UnsupportedOperation as e:
    print(e)