Inconsistent current directory after drive dismount/mount

[k128]

Bug report

Bug description:

After disconnecting and reconnecting my external hard drive (with my current working directory on it), I get surprising results from the os:

>>> os.path.exists('test.csv')
False
>>> os.path.exists(os.path.join(os.getcwd(),'test.csv'))
True
>>> 'test.csv' in list(os.listdir())
True
>>> file=open('test.csv','r')
Traceback (most recent call last):
  File "<python-input-200>", line 1, in <module>
    file=open('test.csv','r')
OSError: [Errno 22] Invalid argument: 'test.csv'

Expected behavior: Keep the same working directory and only throw an error or return os.path.exists()=False if it is inaccessible at runtime.

CPython versions tested on:

3.13

Operating systems tested on:

Windows

[ericvsmith]

The current directory is invalid. Programs need to be able to deal with this. The only thing that surprises me is that os.listdir doesn't return an error. And maybe the first example of exists should raise an exception, but I think there's a history of exists swallowing exceptions.

[encukou]

This is expected behaviour.

In this situation, the current directory does not exist any more. Paths relative to it can't refer to existing files.

But there's a new directory with the same name, so an absolute path (via os.path.join(os.getcwd(), ...) can name an existing file.

(At least that's how it is on Unix, but based on your report, Windows seems to behave the same way.)