Category: Open Source

So, I tried something simple yesterday adding a call to anydbm to a python program that I plan to distribute on windows with py2exe. Doing so I ran into this error:

ImportError: no dbm clone found; tried ['dbhash', 'gdbm', 'dbm',  'dumbdbm']

Turns out that the way py2exe works though it misses the dependency that anydbm has on a db module. The moral of the story is that if you want to use anydbm and py2exe you need to do something like:

import anydbm, dbhash

f = anydbm.open("dbname.db", "c")
...

I’ve been meaning to sit down and play with sqlalchemy for a while now. As an old person though my needs are a little different. Most people use the ORM model to relieve themselves of the burden of dealing with SQL database engines. This is all fine and dandy if you have the luxury of using an SQL database solely as a repository for data with permanence. However, SQL databases can do much more than that. In this vein the sqlalchemy tutorials don’t tell you much about database introspection, that is figuring out what the layout of a table is from the information available in the database. Introspection is very important to me because I frequently create tables (and contraints and triggers etc) on the database. I also have a frequent need to an SQL feature called views but that’s a story for a different day. I came up with this code:

#! /usr/bin/env python

''' ============================================================================================
Program: sqla.py -- A test of sqlalchemy's ability to introspect tables from a database.
============================================================================================ '''

from sqlalchemy import *
from sqlalchemy.orm import *

metadata = MetaData("mysql://scott:tiger@mysql.example.com/test")

workEntryMeta = Table('work_entry', metadata,
                      Column('work_entry_id', Integer, primary_key=True),
                      autoload=True, )

class WorkEntry(object):
    pass

def sqlToStr(c):
    if c is None:
        return "NULL"
    else:
        return str(c)

mapper(WorkEntry, workEntryMeta)

session = create_session()
q = session.query(WorkEntry)
entries = q.all()

headers = None
for e in entries:
    if headers is None:
        headers = [ c for c in e.__dict__.keys() if c[0] <> '_' ]
        print headers
        print "\t".join(headers)

    d = [ sqlToStr(e.__dict__[c]) for c in headers ]
    print "\t".join(d)

This creates an ORM object for the table work_entry in the current python program and grabs all the rows from the database printing each one as it goes.

It looks like the Exodus XMPP/Jabber client has a new home here. I found out because a friend had signed up of a gmail account and wanted to use a real chat client. As an old Jabber user I told her about Exodus.

I always have to look this up. To reload a zone on bind 9 where the server is running split horizon you need: rndc reload Class is almost always going to be “in”. In my case this works out to: rnd reload example.com in inside