On Fri, Feb 13, 2009 at 5:37 AM, Philip Cooper <philip.e...@tesco.net> wrote: > Dear Tutor, > > I am preparing a data base saving it with pickle. I want to add additional > information to the data base but seem to to have to recover the whole file > from disc then add to it and save it again. Is there and append function > within Pickle that will add information to the end of an existing file, > similar to the append fuction used with text files, without recovering the > file from the disc. The data file will eventually be quite large and I can > see a time coming when there will be a time delay problem.
Pickle loads and saves whole objects. You can have multiple objects in one file but if one object changes you have to re-write the file. So if your database object is for example a big dict in which you are changing or adding elements, you will have to rewrite the whole dict. The shelve module provides a persistent dict that might be better suited to what you are doing. But it sounds like you might be well served by using a real database such as SQLite, which comes with recent versions of Python. Kent _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
