ptmcg
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ptmcg-pm.bsky.social
ptmcg
@ptmcg-pm.bsky.social
11 followers 35 following 27 posts
Author/maintainer of pyparsing, littletable, plusminus, logmerger; co-author of Python in a Nutshell 4th edition
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ptmcg-pm.bsky.social
Featured this week on the Artsy Shark website! Includes some of my favorite pieces, and some backstory on how they all came about.

Featured Artist Paul McGuire www.artsyshark.com/2026/01/26/f...
Featured Artist Paul McGuire | Artsy Shark
Blending math and imagination, Paul McGuire creates fractal-inspired images that reveal unexpected beauty in algorithmic form. View more on his
www.artsyshark.com
January 27, 2026 at 5:13 PM
Reposted by ptmcg
colton.boo
If you're a Python developer using Claude Code, or something similar, we just published a blog that covers 10 rules we add to our prompt for drastically improved code gen.

And we include the full prompt at the end of the post!

dagster.io/blog/dignifi...
January 9, 2026 at 5:26 PM
ptmcg-pm.bsky.social
This past weekend I pushed version 3.3.1 of pyparsing to PyPI (3.3.0 had a small but CI-stopping packaging blip). Includes AI instructions of pyparsing best practices. Deprecated camelCase names now throw DeprecatedWarnings. TINY teaching language parser+REPL
#PythonDevelopment #python #pyparsing
Snippet of AI instructions, available by calling `pyparsing.show_best_practices()` from Python Example showing DeprecationWarning raised when calling pyparsing `parseString` instead of `parse_string` TINY code example of a leap year determination function. Complete code: int is_divisible(int a, int b) { float quo := a / b; int iquo := quo; return quo = iquo; } int is_leap_year(int yr) { int div_by_400 := is_divisible(yr, 400); if div_by_400 then return 1; end int div_by_100 := is_divisible(yr, 100); if div_by_100 then return 0; end int div_by_4 := is_divisible(yr, 4); return div_by_4; } int main() { string s; int year; int this_year; read this_year; repeat read yr; if yr = "q" then return 0; end year := yr; is_leap := is_leap_year(year); write year; write " "; if is_leap then if year > this_year then write "will be"; elseif year < this_year then write "was"; else write "is"; end else if year > this_year then write "will not be"; elseif year < this_year then write "was not"; else write "is not"; end end write " a leap year"; write endl; until 0 }
December 25, 2025 at 4:46 AM
ptmcg-pm.bsky.social
I just published pyparsing version 3.3.0b1, with some significant additions:
- example implementation of the TINY language
- performance tests with scripts to run and tabulate results using pyparsing 3.1-3.3 and Python 3.9-3.14

Github link: github.com/pyparsing/py...

#pyparsing #python #parsing
Release Pyparsing 3.3.0b1 · pyparsing/pyparsing
(added in 3.3.0b1) Implemented a TINY language parser/interpreter using pyparsing, in the examples/tiny directory. This is a little tutorial language that I used to demonstrate how to use pyparsi...
github.com
November 26, 2025 at 3:18 AM
ptmcg-pm.bsky.social
Mini-gallery of business card-sized prints of my artwork. Submitting these to the Bee Cave Arts Foundation's Christmas Fair. Prints by moo.com #art #digitalart #beecaveartsfoundation
12 prints of colorful abstract art by Paul McGuire, printed on business cards with simple white and black frames. Arranged on my kitchen table, quarter show for scale.
October 1, 2025 at 5:42 AM
ptmcg-pm.bsky.social
The upcoming 3.3.0 release of pyparsing will include AI instructions for best practices when using this package. They can be accessed from the command-line using `python -m pyparsing.ai.show_best_practices` (They work for human developers too.) #python #pythondev #pyparsing #ai
Snippet extracted from the AI instructions that will be bundled with the upcoming 3.3.0 release of pyparsing: $ python -m pyparsing.ai.show_best_practices <!-- This file contains instructions for best practices for developing parsers with pyparsing, and can be used by AI agents when generating Python code using pyparsing. --> ## Planning - If not provided or if target language definition is ambiguous, ask for examples of valid strings to be parsed - Before developing the pyparsing expressions, define a Backus-Naur Form definition and save this in docs/grammar.md. Update this document as changes are made in the parser. ## Implementing - Import pyparsing using "import pyparsing as pp", and use that for all pyparsing references. - When writing parsers that contain recursive elements (using Forward() or infix_notation()), immediately enable packrat parsing for performance: `pp.ParserElement.enable_packrat()` (call this right after importing pyparsing). See https://pyparsing-docs.readthedocs.io/en/latest/HowToUsePyparsing.html. - For recursive grammars, define placeholders with `pp.Forward()` and assign later using the `<<=` operator; give Forwards meaningful names with `set_name()` to improve errors. - Use PEP8 method and argument names in the pyparsing API ("parse_string", not "parseString"). - Do not include expressions for matching whitespace in the grammar. Pyparsing skips whitespace by default. ...
September 29, 2025 at 5:51 AM
ptmcg-pm.bsky.social
Greetings, BlueSky-ers! I'm new here so I wanted to do a quick introduction. My name is Paul McGuire, I've been using Python for about 24 years. I maintain the #pyparsing package, which is about to have its release 3.3.0 next month. I also make digital art. #PythonDev #Python #Introduction
A digital art abstract image of blues and greens, with a ragged white bottom. The title of this piece is "wave" A digital art abstract image, mostly white, but with a field of pale colors in the lower left corner, with a ragged diagonal border running from upper left to lower right. In the middle of this border is an irregular clump of color, as if it were a stain from multiple colors of ink, washed over the side of a snowy ridge. The title of this piece is "water music II".
September 28, 2025 at 4:33 PM