B014 recommends except ():

[robinst]

In the following code:

    try:
        with open(fn) as f:
            return f.read().split('\n')
    except (OSError, IOError):
        pass

The new B014 warning shows this:

B014 Redundant exception types in except (OSError, IOError):. Write except ():, which catches exactly the same exceptions.

Doesn't seem to make sense to me. Is this a bug 🐻?

[cooperlees]

Thanks for the report, seems buggy to me. If someone does not beat me, I'll try add a test in the next few days and see if I can work out the bug.

[AlexandreYang]

I guess you are using Python3.

We encountered the same case: DataDog/integrations-core#5389

That's because in Python 3 OSError and IOError are equal.

$ python2 -c "print(OSError == IOError)"
False
$ python3 -c "print(OSError == IOError)"
True

In our case, we still need to support both Python 2 and Python 3 for now, hence we chose to # noqa: B014 that line.

Details

For Python 3:

Changed in version 3.3: EnvironmentError, IOError, WindowsError, socket.error, select.error and mmap.error have been merged into OSError, and the constructor may return a subclass.

But in Python 2 IOError and OSError are still conceptually two different error classes.

BaseException
 +-- Exception
      +-- StandardError
      |    +-- EnvironmentError
      |    |    +-- IOError
      |    |    +-- OSError
      |    |         +-- WindowsError (Windows)
      |    |         +-- VMSError (VMS)

source: https://docs.python.org/2/library/exceptions.html

[cooperlees]

Thanks for the insightful explanation.

[deveshks]

Is there any other fix for this issue if the code in question supports both Python 2 and Python 3 apart from adding # noqa: B014 ?

I am trying to add flake8-bugbear support for pip and this line complains with

B014 Redundant exception types in `except (OSError, IOError):`.  
Write `except ():`, which catches exactly the same exceptions.