[Tutor] Dictionary of dictionaries of dictionaries of lists. (original) (raw)

Morten Liebach m at mongers.org
Wed Jul 7 12:36:40 CEST 2004

Hi

I'm writing code to generate my static weblog pages, later rsync'ed to the server (I can't and won't run serverside programs on it), from a PostgreSQl database. Each entry have a 'id' and 'date' field, and I want a datastructure of a dictionary (named "entries") with years as keys, values of a dictionary with months as keys, holding a dictionary with days as keys, value of a list of id's for entries that day.

I have the following code:

""" import psycopg

connection = psycopg.connect("dbname=blog user=m") cursor = connection.cursor()

cursor.execute("SELECT id, date FROM blog") idx = cursor.fetchall() entries = {} for i in range(len(idx)): entries[idx[i][1].year] =
{idx[i][1].month : {idx[i][1].day : [].append(idx[i][0])}}

print idx[23] print entries[2004] """

The output: """ (30, <DateTime object for '2003-03-02 19:44:58.00' at 3c118a68>) {4: {20: None}} """

The first line is OK, but in the second one I expected something more like: """ {1: {1: [67], 3: [68], 4: [69, 70]}, 2: {17: [71]}} """

(Not exactly the entries in my database, there's a lot more, but you get the picture I hope)

I'm clearly doing something wrong. Something's missing, but what, and (more important) why? I might have stared myself blind on this problem by now, so I need a push. :-) Maybe even a rethink of it all.

I'm a python beginner, but not new to programming. I've been doing mostly perl and some C# the last year.

I use OpenBSD 3.5-current, Python 2.3.3, psycopg 1.1.11, mxDateTime 2.0.5 and PostgreSQL 7.4.2.

Have a nice day Morten

-- http://m.mongers.org/ -- http://gallery.zentience.org/ END

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