rdbms-subsetter

I've never had a tool I really liked that would extract a chunk of a large production database for testing purposes while respecting the database's foreign keys. This past week I finally got to write one: rdbms-subsetter.

rdbms-subsetter postgresql://user:passwd@host/source_db postgresql://user:passwd@host/excerpted_db 0.001

Getting it to respect referential integrity "upward" - guaranteeing every needed parent record would be included for each child row - took less than a day. Trying to get it to also guarantee (more...)

%sql: To Pandas and Back

A Pandas DataFrame has a nice to_sql(table_name, sqlalchemy_engine) method that saves itself to a database.

The only trouble is that coming up with the SQLAlchemy Engine object is a little bit of a pain, and if you're using the IPython %sql magic, your %sql session already has an SQLAlchemy engine anyway. So I created a bogus PERSIST pseudo-SQL command that simply calls to_sql with the open database connection:

%sql PERSIST mydataframe

The result is (more...)

auto-generate SQLAlchemy models

PyOhio gave my lightning talk on ddlgenerator a warm reception, and Brandon Lorenz got me thinking, and PyOhio sprints filled my with py-drenaline, and now ddlgenerator can inspect your data and spit out SQLAlchemy model definitions for you:


$ cat merovingians.yaml
-
name: Clovis I
reign:
from: 486
to: 511
-
name: Childebert I
reign:
from: 511
to: 558
$ ddlgenerator --inserts sqlalchemy merovingians.yaml

from sqlalchemy import create_engine, Column, Integer, Table, Unicode
engine (more...)

18F

Yesterday was my first day at 18F!

What is 18F? We're a small, little-known government organization that works outside the usual channels to accomplish special projects. It involves black outfits and a lot of martial arts.

Kidding! Sort of. 18F is a new agency within the GSA that does citizen-focused work for other parts of the U.S. Government, working small, quick projects to make information more accessible. We're using all the tricks: small teams, (more...)

ddlgenerator

I've had it on github for a while, but I finally released ddlgenerator to PyPI.

I've been frustrated for years that there was no good open-source way to set up RDBMS tables from flat data files. Sure, you could import the data - after setting up the DDL by hand. ddlgenerator handles that; in fact, you can go from zero, setting up and populating a table in a single line. Nothing up my sleeve:


$ (more...)

data_dispenser

I went down a refactoring rabbit hole on ddl-generator and ended up pulling out the portion that pulls in data from various file formats. Perhaps it will be useful to others.


>>> from data_dispenser.sources import Source
>>> for row in Source('animals.csv'):
... print(row)
...
OrderedDict([('name', 'Alfred'), ('species', 'wart hog'), ('kg', '22'), ('notes', 'loves turnips')])
OrderedDict([('name', 'Gertrude'), ('species', 'polar bear'), ('kg', '312.7'), ('notes', 'deep thinker')])
OrderedDict([('name', 'Emily'), ('species', 'salamander'), ('kg', '0.3'), ('notes', '')])

Basically, (more...)

G+ Public Hangout Fail

tl;dr:Do not use public Google+ Hangouts under any circumstances, because people suck.

Before the PyCon 2014 CFP came due, PyLadies hosted several G+ hangouts for talk proposal brainstorming. Potential speakers could talk over and flesh out their ideas with each other, producing better talk proposals. More importantly, it was a nice psychological stepping stone on the way to filling out that big, scary CFP form all alone. I thought they went great.

I wanted (more...)

TRUCEConf

Please consider participating in TRUCEConf (March 18-19 in Cincinnati)!

The goal is to help the tech community heal, through learning from others outside our industry and having an open dialogue and on how we can be better humans to each other in the world of tech.

You may remember fierce controversy around TRUCEConf when virtually nothing was known about it but its name; without solid information, it was easy to read bad connotations into the (more...)