# A wrapper around the (optional) built-in class dbm, supporting keys# and values of almost any type instead of just string.# (Actually, this works only for keys and values that can be read back# correctly after being converted to a string.)  class Dbm:     def __init__(self, filename, mode, perm):        import dbm        self.db = dbm.open(filename, mode, perm)     def __repr__(self):        s = ''        for key in self.keys():            t = repr(key) + ': ' + repr(self[key])            if s: t = ', ' + t            s = s + t        return '{' + s + '}'     def __len__(self):        return len(self.db)     def __getitem__(self, key):        return eval(self.db[repr(key)])     def __setitem__(self, key, value):        self.db[repr(key)] = repr(value)     def __delitem__(self, key):        del self.db[repr(key)]     def keys(self):        res = []        for key in self.db.keys():            res.append(eval(key))        return res     def has_key(self, key):        return self.db.has_key(repr(key))  def test():    d = Dbm('@dbm', 'rw', 0600)    print d    while 1:        try:            key = input('key: ')            if d.has_key(key):                value = d[key]                print 'currently:', value            value = input('value: ')            if value == None:                del d[key]            else:                d[key] = value        except KeyboardInterrupt:            print ''            print d        except EOFError:            print '[eof]'            break    print d  test()