Is there a way to register a file so that it is deleted when Python exits, regardless of how it exits? I am using long-lived temporary files and want to ensure they are cleaned up.
The file must have a filename and it's original handle should be closed as soon as possible -- there will be thousands of these created and I need to ensure they exist only as normal files.
Use the tempfile module; it creates temporary files that auto-delete.
From the tempfile.NamedTemporaryFile() documentation:
If delete is true (the default), the file is deleted as soon as it is closed.
You can use such a file object as a context manager to have it closed automatically when the code block exits, or you leave it to be closed when the interpreter exits.
The alternative is to create a dedicated temporary directory, with tempdir.mkdtemp(), and use shutil.rmtree() to delete the whole directory when your program completes.
Preferably, you do the latter with another context manager:
import shutil
import sys
import tempfile
from contextlib import contextmanager
@contextmanager
def tempdir():
path = tempfile.mkdtemp()
try:
yield path
finally:
try:
shutil.rmtree(path)
except IOError:
sys.stderr.write('Failed to clean up temp dir {}'.format(path))
and use this as:
with tempdir() as base_dir:
# main program storing new files in base_dir
# directory cleaned up here
You could do this with a atexit hook function, but a context manager is a much cleaner approach.