Op 31/03/2026 om 9:48 schreef Anders Munch:
Rob Cliffe via Python-list<[email protected]> wrote:
> When the RAM disc is empty,
> os.scandir("R:")
> raises a FileNotFoundError instead of (as I would have expected) returning an
empty iterator.
os.scandir is a simple wrapper around FindFirstFile/FindNextFile. If
FindFirstFileW("R:", "*.*") sets the file-not-found Windows error code, then
that will be turned into the exception that you see.
I can confirm this. I wrote a small test directly using FindFirstFileW()
(in C++, though you could do it in Python using ctypes), with the
following result:
(Z is an empty RAM disk, EmptyDir is a regular empty directory on my
hard disk, D is an empty flash drive)
Z: ERROR_FILE_NOT_FOUND
Z:\ ERROR_FILE_NOT_FOUND
Z:\*.* ERROR_FILE_NOT_FOUND
EmptyDir OK
EmptyDir\ ERROR_INVALID_PARAMETER
EmptyDir\*.* OK
D: ERROR_FILE_NOT_FOUND
D:\ ERROR_FILE_NOT_FOUND
D:\*.* OK
There doesn't seem to be much consistency.
As you can see, FindFirstFileW() on an empty RAM disk gives an
ERROR_FILE_NOT_FOUND. Adding \ or \*.*. Doesn't help.
Weirdly enough adding \*.* does help for the empty flash drive.
You might want to try os.scandir("R:\\"). Your issue could have something to
do with the current directory for the R: drive not being well-defined.
I tried it; doesn't make a difference.
I think your best bet is to simply handle the FileNotFoundError
exception manually in your code. Perhaps best to write your own wrapper
around os.scandir() that does that.
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