Deleting keys from shelve

[Olaf Meding]

Why does a shelve file never get smaller?

I noticed that the shelve file (db.txt, see below) does not change
(get smaller) when deleting a key.  The key is deleted but the file
size does not change.  I expected the db.txt file to get smaller.

def delete():
  s = shelve.open('db.txt')
  del s['test3']
  s.close()

I am using Python 2.2.1 on MS Windows.  Thanks so much for your help.

Olaf