1,070 items tagged “python”
The Python programming language.
2023
Fleet Context. This project took the source code and documentation for 1221 popular Python libraries and ran them through the OpenAI text-embedding-ada-002 embedding model, then made those pre-calculated embedding vectors available as Parquet files for download from S3 or via a custom Python CLI tool.
I haven’t seen many projects release pre-calculated embeddings like this, it’s an interesting initiative.
See the History of a Method with git log -L (via) Neat Git trick from Caleb Hearth that I hadn’t seen before, and it works for Python out of the box:
git log -L :path_with_format:__init__.py
That command displays a log (with diffs) of just the portion of commits that changed the path_with_format function in the __init__.py file.
My User Experience Porting Off setup.py (via) PyOxidizer maintainer Gregory Szorc provides a detailed account of his experience trying to figure out how to switch from setup.py to pyproject.toml for his zstandard Python package.
This kind of detailed usability feedback is incredibly valuable for project maintainers, especially when the user encountered this many different frustrations along the way. It’s like the written version of a detailed usability testing session.
chDB (via) This is a really interesting development: chDB offers “an embedded SQL OLAP Engine” as a Python package, which you can install using “pip install chdb”. What you’re actually getting is a wrapper around ClickHouse—it’s almost like ClickHouse has been repackaged into an embedded database similar to SQLite.
I’m banned for life from advertising on Meta. Because I teach Python. (via) If accurate, this describes a nightmare scenario of automated decision making.
Reuven recently found he had a permanent ban from advertising on Facebook. They won’t tell him exactly why, and have marked this as a final decision that can never be reviewed.
His best theory (impossible for him to confirm) is that it’s because he tried advertising a course on Python and Pandas a few years ago which was blocked because a dumb algorithm thought he was trading exotic animals!
The worst part? An appeal is no longer possible because relevant data is only retained for 180 days and so all of the related evidence has now been deleted.
Various comments on Hacker News from people familiar with these systems confirm that this story likely holds up.
Bottleneck T5 Text Autoencoder (via) Colab notebook by Linus Lee demonstrating his Contra Bottleneck T5 embedding model, which can take up to 512 tokens of text, convert that into a 1024 floating point number embedding vector... and then then reconstruct the original text (or a close imitation) from the embedding again.
This allows for some fascinating tricks, where you can do things like generate embeddings for two completely different sentences and then reconstruct a new sentence that combines the weights from both.
New sqlite3 CLI tool in Python 3.12. The newly released Python 3.12 includes a SQLite shell, which you can open using “python -m sqlite3”—handy for when you’re using a machine that has Python installed but no sqlite3 binary.
I installed Python 3.12 for macOS using the official installer from Python.org and now “/usr/local/bin/python3 -m sqlite3” gives me a SQLite 3.41.1 shell—a pleasantly recent version from March 2023 (the latest SQLite is 3.43.1, released in September).
[On Python 3.12 subinterpreters] there's massive advantages for mixed C(++) and Python: I can now have multiple sub interpreters running concurrently and accessing the same shared state in a thread-safe C++ library.
Previously this required rewriting the whole C++ library to support either pickling (multiplying the total memory consumption by the number of cores), or support allocating everything in shared memory (which means normal C++ types like
std::stringare unusable, need to switch e.g. toboost::interprocess).Now is sufficient to pickle a pointer to a C++ object as an integer, and it'll still be a valid pointer in the other subinterpreter.
— ynik
Get Your Mac Python From Python.org. Glyph recommends the official Python installer from python.org as the best way to get started with a Python environment on macOS—with require-virtualenv = true in your ~/.pip/pip.conf to help avoid accidentally installing global packages.
Things I’ve learned about building CLI tools in Python
I build a lot of command-line tools in Python. It’s become my favorite way of quickly turning a piece of code into something I can use myself and package up for other people to use too.
[... 1,235 words]A Hackers’ Guide to Language Models. Jeremy Howard’s new 1.5 hour YouTube introduction to language models looks like a really useful place to catch up if you’re an experienced Python programmer looking to start experimenting with LLMs. He covers what they are and how they work, then shows how to build against the OpenAI API, build a Code Interpreter clone using OpenAI functions, run models from Hugging Face on your own machine (with NVIDIA cards or on a Mac) and finishes with a demo of fine-tuning a Llama 2 model to perform text-to-SQL using an open dataset.
How CPython Implements and Uses Bloom Filters for String Processing. Fascinating dive into Python string internals by Abhinav Upadhyay. It turns out CPython uses very simple bloom filters in several parts of the core string methods, to solve problems like splitting on newlines where there are actually eight codepoints that could represent a newline, and a tiny bloom filter can help filter a character in a single operation before performing all eight comparisons only if that first check failed.
bpy—Blender on PyPI (via) TIL you can “pip install” Blender!
bpy “provides Blender as a Python module”—it’s part of the official Blender project, and ships with binary wheels ranging in size from 168MB to 319MB depending on your platform.
It only supports the version of Python used by the current Blender release though—right now that’s Python 3.10.
Understanding Immortal Objects in Python 3.12. Abhinav Upadhyay provides a clear and detailed explanation of immortal objects coming in Python 3.12, which ensure Python no longer updates reference counts for immutable objects such as True, False, None and low-values integers. The trick (which maintains ABI compatibility) is pretty simple: a reference count value of 4294967295 now means an object is immortal, and the existing Py_INCREF and Py_DECREF macros have been updated to take that into account.
Lark parsing library JSON tutorial (via) A very convincing tutorial for a new-to-me parsing library for Python called Lark.
The tutorial covers building a full JSON parser from scratch, which ends up being just 19 lines of grammar definition code and 15 lines for the transformer to turn that tree into the final JSON.
It then gets into the details of optimization—the default Earley algorithm is quite slow, but swapping that out for a LALR parser (a one-line change) provides a 5x speedup for this particular example.
deno_python (via) A wildly impressive hack: deno_python uses Deno’s FFI interface to load your system’s Python framework (.dll/.dylib/.so) and sets up JavaScript proxy objects for imported Python objects—so you can run JavaScript code that instantiates objects from Python libraries and uses them to process data in different ways.
The latest release added pip support, so things like ’const np = await pip.import(“numpy”)’ now work.
Llama from scratch (or how to implement a paper without crying) (via) Brian Kitano implemented the model described in the Llama paper against TinyShakespeare, from scratch, using Python and PyTorch. This write-up is fantastic—meticulous, detailed and deeply informative. It would take several hours to fully absorb and follow everything Brian does here but it would provide multiple valuable lessons in understanding how all of this stuff fits together.
Python cocktail: mix a context manager and an iterator in equal parts (via) Explanation of a neat trick used by the Tenacity Python library, which provides a mechanism for retrying a chunk of code automatically on errors up to three times using a mixture of an iterator and a context manager to work around Python’s lack of multi-line lambda functions.
Catching up on the weird world of LLMs
I gave a talk on Sunday at North Bay Python where I attempted to summarize the last few years of development in the space of LLMs—Large Language Models, the technology behind tools like ChatGPT, Google Bard and Llama 2.
[... 10,489 words]A Steering Council notice about PEP 703 (Making the Global Interpreter Lock Optional in CPython) (via) Huge news concerning the nogil research fork of Python: “It’s clear that the overall sentiment is positive, both for the general idea and for PEP 703 specifically. The Steering Council is also largely positive on both. We intend to accept PEP 703, although we’re still working on the acceptance details.”
textual-paint (via) Isaiah Odhner built a full working clone of MS Paint that runs entirely in the terminal, using Textual and Python. It’s worth trying this out to get a feel for quite how much you can get done with a CLI app these days—“pipx install textual-paint” worked for me.
Stamina: tutorial (via) Stamina is Hynek’s new Python library that implements an opinionated wrapper on top of Tenacity, providing a decorator for easily implementing exponential backoff retries. This tutorial includes a concise, clear explanation as to why this is such an important concept in building distributed systems.
Data analysis with SQLite and Python. I turned my 2hr45m workshop from PyCon into the latest official tutorial on the Datasette website. It includes an extensive handout which should be useful independently of the video itself.
Status of Python Versions (via) Very clear and useful page showing the exact status of different Python versions. 3.7 reaches end of life today (no more security updates), while 3.11 will continue to be supported until October 2027.
Building Search DSLs with Django (via) Neat tutorial by Dan Lamanna: how to build a GitHub-style search feature—supporting modifiers like “is:open author:danlamanna”—using PyParsing and the Django ORM.
Symbex: search Python code for functions and classes, then pipe them into a LLM
I just released a new Python CLI tool called Symbex. It’s a search tool, loosely inspired by ripgrep, which lets you search Python code for functions and classes by name or wildcard, then see just the source code of those matching entities.
[... 1,183 words]sqlean.py: Python’s sqlite3 with extensions. Anton Zhiyanov built a new Python package which bundles a fresh, compiled copy of SQLite with his SQLean family of C extensions built right in. Installing it gets you the latest SQLite—3.42.0—with nearly 200 additional functions, including things like define() and eval(), fileio_read() and fileio_write(), percentile_95() and uuid4() and many more. “import sqlean as sqlite3” works as a drop-in replacement for the module from the standard library.
simpleaichat (via) Max Woolf released his own Python package for building against the GPT-3.5 and GPT-4 APIs (and potentially other LLMs in the future).
It’s a very clean piece of API design with some useful additional features: there’s an AsyncAIChat subclass that works with Python asyncio, and the library includes a mechanism for registering custom functions that can then be called by the LLM as tools.
One trick I haven’t seen before: it uses a combination of max_tokens: 1 and a ChatGPT logit_bias to ensure that answers to one of its default prompts are restricted to just numerals between 0 and 9. This is described in the PROMPTS.md file.
pytest-icdiff (via) This is neat: “pip install pytest-icdiff” provides an instant usability upgrade to the output of failed tests in pytest, especially if the assertions involve comparing larger strings or nested JSON objects.
The Python Language Summit 2023: Making the Global Interpreter Lock Optional. Extremely informative update covering Sam Gross’s python-nogil proposal from this year’s language summit at PyCon.
Sam has been working hard on his fork for the past year, and now has it rebased for Python 3.12. If his PEP is accepted it could end up as an optional compile-time build in time for Python 3.13.
“The plan for nogil remains that it would be enabled via a compile-time flag, named --disable-gil. Third-party C extensions would need to provide separate wheels for GIL-disabled Python.”