except OSError as e: if e.errno != errno.EEXIST: raise

This code snippet is a try-except block that handles the OSError exception that may occur when trying to create a directory.

The code tries to create a directory, but if it already exists, it will raise an OSError with the error number errno.EEXIST (which means the directory already exists).

If the OSError has a different error number, it will be raised and handled by the calling function.