[Tutor] Shelve Help!

[Catriona Johnston]

Dear all,
    I have the following error traceback from this line of code:
	code:	db = shelve.open('DataBase', 'w')

	error: 	Traceback (most recent call last):
		File "/users/kjohnston/programs/sequence.py", line 83, in ?
    		    main()
 		File "/users/kjohnston/programs/sequence.py", line 69, in
main
		    seq.store()
		File "/users/kjohnston/programs/sequence.py", line 36, in
store
		    db = shelve.open('DataBase', 'w')
		File "/usr/local/lib/python1.6/shelve.py", line 157, in open
		    return DbfilenameShelf(filename, flag)
  		File "/usr/local/lib/python1.6/shelve.py", line 147, in
__init__
		    Shelf.__init__(self, anydbm.open(filename, flag))
		File "/usr/local/lib/python1.6/anydbm.py", line 83, in open
		    raise error, "db type could not be determined"
		anydbm.error: db type could not be determined

I am afraid I have no idea why I am getting this error, the DataBase file
exists in the same directory as the program is ran from.
Any help as always is appreciated.
Thank you,
Kate