On Apr 12, 7:09 am, Bruno Desthuilliers <[EMAIL PROTECTED]> wrote: > Dag a écrit : > > > > > I have an application which works with lists of tuples of the form > > (id_nr,'text','more text',1 or 0). I'll have maybe 20-50 or so of these > > lists containing anywhere from 3 to over 30000 tuples. The actions I > > need to do is either append a new tuple to the end of the list, display > > all the tuples or display all the tuples where the last element is a 1 > > > Basically what I'm wondering is the best way to store these data stuctures > > to disc. As the subject mentioned I've basically got three approaches. > > Store each list as a text file, pickle each list to file or shove the > > whole thing into a bunch of database tables. I can see pros and cons > > with each approach. Does anybody have any advice as to whether any of > > these approaches is obviously better than any other? On one hand I like > > the text file approach since it lets me append without loading > > everything into memory, on the other hand the sqlite approach makes it > > easy to select stuff with SELECT * FROM foo WHERE... which could be > > handy if ever need to add more advanced filtering.
s/if/when/ > > Given your specs, I'd go for SQLite without any hesitation. Your data > structure is obviously relational (a list of tuples is a pretty good > definition of a relation), so a relational DBMS is the obvious solution, > and you'll get lots of other benefits from it (SQL being only one of > them - you can also think about free optimization, scalability, and > interoperability). And if you don't like raw SQL and prefer something > more pythonic, then you have SQLAlchemy and Elixir. > > My 2 cents... ... and a few more cents: There are *two* relations/tables involved (at least): a "tuple" table and a "list" table. The 20-50 or so lists need a unique name or number each, and other attributes of a list are sure to come out of the woodwork later. Each tuple will need a column containing the ID of the list it belongs to. It's a bit boggling that (1) each tuple has an id_nr but there's no requirement to query on it (2) req. only to "append" new tuples w/o checking id_nr already exists (3) req. to "display" all of 30,000 tuples ... -- http://mail.python.org/mailman/listinfo/python-list
