Skip to main content

The best PyCon talk you didn't see

There were a lot of good talks at PyCon but I humbly submit that the best one you haven't seen yet is Robert Brewer's talk on DejaVu. Robert describes how his Geniusql layer disassembles and parses python bytecode to let his ORM turn python lambdas into SQL. Microsoft got a lot of press for doing something similar for .NET with LINQ, but Bob was there first.
  box = store.new_sandbox()
print [c.Title for c in box.recall(
  Comic, lambda c: 'Hob' in c.Title or c.Views > 0)]
This is cool as hell. The Geniusql part start about 15 minutes in.

Comments

Unknown said…
Erlang has had this for a very long time too, at least for Mnesia databases, e.g. Mnemosyne and later QLC. Cool stuff :)
Jason Baker said…
Hah! I proved you wrong. I did see that talk. Shows you.

Seriously though, I've been meaning to try dejavu out for a while and this gives me new impetus to give it a shot.
Rob De Almeida said…
I did something similar: a DB API wrapper that parses the source code to build the SQL:

http://pypi.python.org/pypi/simpleQL

The only problem is that it doesn't work on an interactive session, since it needs to read the source code.
Unknown said…
I liked it a lot, too. I haven't yet had time to figure out if I want to use DejaVu in general, but the principle is a great one: why make people learn a new syntax for something (like filtering rows) when they already know a perfectly good syntax for it?

Popular posts from this blog

The Missing Piece in AI Coding: Automated Context Discovery

I recently switched tasks from writing the ColBERT Live! library and related benchmarking tools to authoring BM25 search for Cassandra . I was able to implement the former almost entirely with "coding in English" via Aider . That is: I gave the LLM tasks, in English, and it generated diffs for me that Aider applied to my source files. This made me easily 5x more productive vs writing code by hand, even with AI autocomplete like Copilot. It felt amazing! (Take a minute to check out this short thread on a real-life session with Aider , if you've never tried it.) Coming back to Cassandra, by contrast, felt like swimming through molasses. Doing everything by hand is tedious when you know that an LLM could do it faster if you could just structure the problem correctly for it. It felt like writing assembly without a compiler -- a useful skill in narrow situations, but mostly not a good use of human intelligence today. The key difference in these two sce...

A week of Windows Subsystem for Linux

I first experimented with WSL2 as a daily development environment two years ago. Things were still pretty rough around the edges, especially with JetBrains' IDEs, and I ended up buying a dedicated Linux workstation so I wouldn't have to deal with the pain.  Unfortunately, the Linux box developed a heat management problem, and simultaneously I found myself needing a beefier GPU than it had for working on multi-vector encoding , so I decided to give WSL2 another try. Here's some of the highlights and lowlights. TLDR, it's working well enough that I'm probably going to continue using it as my primary development machine going forward. The Good NVIDIA CUDA drivers just work. I was blown away that I ran conda install cuda -c nvidia and it worked the first try. No farting around with Linux kernel header versions or arcane errors from nvidia-smi. It just worked, including with PyTorch. JetBrains products work a lot better now in remote development mod...

Python at Mozy.com

At my day job, I write code for a company called Berkeley Data Systems. (They found me through this blog, actually. It's been a good place to work.) Our first product is free online backup at mozy.com . Our second beta release was yesterday; the obvious problems have been fixed, so I feel reasonably good about blogging about it. Our back end, which is the most algorithmically complex part -- as opposed to fighting-Microsoft-APIs complex, as we have to in our desktop client -- is 90% in python with one C extension for speed. We (well, they, since I wasn't at the company at that point) initially chose Python for speed of development, and it's definitely fulfilled that expectation. (It's also lived up to its reputation for readability, in that the Python code has had 3 different developers -- in serial -- with very quick ramp-ups in each case. Python's succinctness and and one-obvious-way-to-do-it philosophy played a big part in this.) If you try it out, pleas...