persistence - Python 'shelve' that writes itself to disk after each operation -

i'm doing project in python involves lot of interactive work persistent dictionary. if weren't doing interactive development, use contextlib.closing , confident shelf written disk eventually. stands there's no chunk of code can wrap within 'with' statement. i'd prefer not have trust myself call close() on shelf @ end of session.

the amount of data involved not large, , happily sync shelf disk after each operation. i've found myself writing wrapper shelve i'm not strong enough python programmer identify correct set of dict methods i'd need override. , seems me if i'm doing idea, it's been done before. paradigmatically correct way handle this?

i'll add using shelve because it's simple module, , comes python. if possible i'd prefer avoid doing requires (for example) pulling in complicated library dealing databases.

i'm using winxp sp3, python 2.7.5 via anaconda 1.6.2 (32-bit), , running inside spyder. can tell looking @ modified times file backing shelf shelf isn't updating until call sync or close.

what can subclass dbfilenameshelf , override __setitem__ , __delitem__ automatically sync after each change. work (untested):

from shelve import dbfilenameshelf  class autosyncshelf(dbfilenameshelf):     # default newer pickle protocol , writeback=true     def __init__(self, filename, protocol=2, writeback=true):         dbfilenameshelf.__init__(self, filename, protocol=protocol, writeback=writeback)     def __setitem__(self, key, value):         dbfilenameshelf.__setitem__(self, key, value)         self.sync()     def __delitem__(self, key):         dbfilenameshelf.__delitem__(self, key)         self.sync()  my_shelf = autosyncshelf("myshelf") 

i can't vouch performance of this, of course.