Bug report

Calling theclear method on ashelve.Shelf object takes a very long time on databases that have thousands of entries.

It can be seen in this script, which creates a database with 10,000 entries and immediately clears it.

importosimportshelveimporttempfilewithtempfile.TemporaryDirectory()astempdir:filename=os.path.join(tempdir,"test-shelf")withshelve.open(filename)asdb:items= {str(x):xforxinrange(10000)}db.update(items)db.clear()print("ok")

On my M2 Mac Mini, this script takes about 2.1 seconds.

james@iris ~ % time python shelve-clear-test.pyokpython shelve-clear-test.py  1.18s user 0.92s system 99% cpu 2.100 total

On a Debian VPS:

james@asteroid:~$ time python3 shelve-clear-test.py okreal0m43.665suser0m34.330ssys0m9.107s

Your environment

• CPython versions tested on
  • 3.11.2
  • 3.11.4
  • cpython/main branch
• Operating system and architecture
  • macOS/arm64 13.4.1
  • Debian/x86_64 12.1

Linked PRs

• gh-107089: Improve Shelf.clear method performance #107090