[Tutor] Method to create small and simple database

[Peter Otten]

Joel Montes de Oca wrote:

> Hello everyone,
> 
> About me:
> 
> This is the first time I post to Tutor at Python.org.
> 
> I am brand spanking new to Python. I can create simple application, gone
> through a few tutorials and watched the Google Python 2 day class on
> Youtube. (List of classes: http://goo.gl/Ud5rg)
> 
> Just yesterday I figured out how to load up a GUI made in Glade and pass
> singles around and what not. Huge accomplishment for me since
> documentation is a bit shaky for noobs like me. :)
> 
> I have some programming knowledge. I learned (self tough) VB when I was
> in middle school and then did a intro to C++ in college. Of course
> mentioning that is trivial since I haven't done any programming for
> about 5 years or so.. But I do know basic concepts. Just need a little
> push in the right direction..
> 
> --------------------------------------
> 
> I think I know how to design my application but I would like to put it
> on here for you guys to review and provide me with feedback/suggestions
> as to the best way to go about it.
> 
> --------------------------------------
> 
> The application:
> 
> I want to build a simple application that keeps track of items borrowers
> check out. So the end user types in the names of /borrowers/ and also
> types in a list of /items/. Then the end user checks out the /items/ to
> the /borrowers/.
> 
> The category that my application would fall under is close to
> /collection management tools/. Here's a list of a few other applications
> that do something like what I am aiming for:
> http://www.makeuseof.com/tag/4-open-source-collection-manager-apps/
> 
> In addition to the application keeping track of who has what, I would
> like to code the date the items are out, which borrowers have not
> borrowed anything in the last month, and so on. That said, I need to
> setup some kind of database like file. I don't want to have a database
> server though.
> 
> The reason I want to build a new tool is because:
> 
>     A) I want to play around with Python
>     B) My friend needs the application to be simple and geared to his
>     needs without too many extra bells & whistles
> 
> 
> --------------------------------------
> 
> 
> My method:
> 
> I was thinking of using the lxmal module to construct a XML file to
> read/write all the information.
> 
> I figured this was the easiest way to do what I need since the
> information is setup as a tree. (Easy to think about and see) Example:
> 
> <app>
> <borrowers>
> 
> <user>John Doe</user>
> 
> <checked out> Item1:Item2:||2011/4/2</checked out>
> 
> <user>Mary Doe</user>
> 
> <checked out> Item3||2011/7/22</checked out>
> 
> </borrowers>
> <objects>
> 
> <item>Item1</item>
> 
> <createdOn>2011/2/1</createdOn>
> 
> <checked_out_times>32</checked_out_times>
> 
> <item>Item2</item>
> 
> <createdOn>2011/2/1</createdOn>
> 
> <checked_out_times>22</checked_out_times>
> 
> <item>Item3</item>
> 
> <createdOn>2011/2/1</createdOn>
> 
> <checked_out_times>1</checked_out_times>
> </objects>
> </app>
> 
> The application will not be used in an enterprise kind of environment.
> The application is meant to hold about 80 borrowers and about 100 items
> and that's about it.
> 
> Is this a good way to go about my project? Is there a better & easier way?
> 
> I don't want to trade off "better" with "easy". Someone once suggested
> on Freenode #Python that I should use a sql database. I don't remember
> the name of it. It was something like lightsql or something like that.
> That particular database didn't use a server end. I guess it spit out a
> txt database or something... This might be a good time to mention I know
> very little about database construction or sql commands.
> 
> Anyhow, I am looking forward to hearing opinion's and suggestions.

Well, using sqlite

http://docs.python.org/library/sqlite3.html

may be both better and easier than lxml, but for the tiny amount of data you 
are planning to handle you can also make do with a few of Python's lists and 
dicts, and use pickle

http://docs.python.org/library/pickle.html

to save the data when you're done. It won't get easier than that.