I wrote a blog post about this year's Advent of Code. I had a blast and I am already looking forward to 2026!
* All my Python solutions were under 1s using pure Python and 100ms with a little help from mypy/scipy
• The AoC community is the best ❤️
blog.pecar.me/advent-of-c...
* All my Python solutions were under 1s using pure Python and 100ms with a little help from mypy/scipy
• The AoC community is the best ❤️
blog.pecar.me/advent-of-c...
Advent of Code 2025 🎄
December is the time for Advent of Code, as it has been since 2015, when the first Advent of Code event was published.
blog.pecar.me
December 14, 2025 at 4:42 PM
I wrote a blog post about this year's Advent of Code. I had a blast and I am already looking forward to 2026!
* All my Python solutions were under 1s using pure Python and 100ms with a little help from mypy/scipy
• The AoC community is the best ❤️
blog.pecar.me/advent-of-c...
* All my Python solutions were under 1s using pure Python and 100ms with a little help from mypy/scipy
• The AoC community is the best ❤️
blog.pecar.me/advent-of-c...
I've finished #adventofcode 2025 and this is the first year that I managed to get all solutions under 100ms ⚡
All but two are under 10ms. Not bad for the slowest popular language out there 🐍, although I did have to use numpy a few times.
All but two are under 10ms. Not bad for the slowest popular language out there 🐍, although I did have to use numpy a few times.
December 12, 2025 at 1:50 PM
I've finished #adventofcode 2025 and this is the first year that I managed to get all solutions under 100ms ⚡
All but two are under 10ms. Not bad for the slowest popular language out there 🐍, although I did have to use numpy a few times.
All but two are under 10ms. Not bad for the slowest popular language out there 🐍, although I did have to use numpy a few times.
It has been 15 years since I joined GitHub 😱
December 7, 2025 at 9:43 AM
It has been 15 years since I joined GitHub 😱
New release of adventofcode PyPI package today improves the display of alternative solutions for each day:
1. Slower solutions are no longer counted in totals
2. Slower solutions are dimmed out
Why limit yourself to one #adventofcode solution per day? 😆
Happy solving! 🎄
1. Slower solutions are no longer counted in totals
2. Slower solutions are dimmed out
Why limit yourself to one #adventofcode solution per day? 😆
Happy solving! 🎄
December 7, 2025 at 6:40 AM
New release of adventofcode PyPI package today improves the display of alternative solutions for each day:
1. Slower solutions are no longer counted in totals
2. Slower solutions are dimmed out
Why limit yourself to one #adventofcode solution per day? 😆
Happy solving! 🎄
1. Slower solutions are no longer counted in totals
2. Slower solutions are dimmed out
Why limit yourself to one #adventofcode solution per day? 😆
Happy solving! 🎄
I compared the first 4 #adventofcode solutions on two different CPUs.
* Rows with a red background are on 8x Intel(R) Core(TM) i7-10510U CPU @ 1.80GHz.
* Rows with a green background are on Apple M3 Max.
So if you want to be better at advent of code just get a better CPU? 😆
* Rows with a red background are on 8x Intel(R) Core(TM) i7-10510U CPU @ 1.80GHz.
* Rows with a green background are on Apple M3 Max.
So if you want to be better at advent of code just get a better CPU? 😆
December 4, 2025 at 1:49 PM
I compared the first 4 #adventofcode solutions on two different CPUs.
* Rows with a red background are on 8x Intel(R) Core(TM) i7-10510U CPU @ 1.80GHz.
* Rows with a green background are on Apple M3 Max.
So if you want to be better at advent of code just get a better CPU? 😆
* Rows with a red background are on 8x Intel(R) Core(TM) i7-10510U CPU @ 1.80GHz.
* Rows with a green background are on Apple M3 Max.
So if you want to be better at advent of code just get a better CPU? 😆
I wonder how long I'll be able to keep all the days green like this #adventofcode 🟢
Today I learned that you can use None when slicing a list in Python:
>>> [1,2,3][:None]
[1, 2, 3]
Useful to avoid the edge case where [:0] would give an empty list:
>>> [1,2,3][:0]
[]
Today I learned that you can use None when slicing a list in Python:
>>> [1,2,3][:None]
[1, 2, 3]
Useful to avoid the edge case where [:0] would give an empty list:
>>> [1,2,3][:0]
[]
December 3, 2025 at 6:21 AM
I wonder how long I'll be able to keep all the days green like this #adventofcode 🟢
Today I learned that you can use None when slicing a list in Python:
>>> [1,2,3][:None]
[1, 2, 3]
Useful to avoid the edge case where [:0] would give an empty list:
>>> [1,2,3][:0]
[]
Today I learned that you can use None when slicing a list in Python:
>>> [1,2,3][:None]
[1, 2, 3]
Useful to avoid the edge case where [:0] would give an empty list:
>>> [1,2,3][:0]
[]
Just launched version 25.4 of my adventofcode PyPI package! 🚀
25.4 adds a `adventofcode run` command that removes the ugly boilerplate that you had to have in your puzzle files until now!
Before: After:
25.4 adds a `adventofcode run` command that removes the ugly boilerplate that you had to have in your puzzle files until now!
Before: After:
December 2, 2025 at 9:00 AM
Just launched version 25.4 of my adventofcode PyPI package! 🚀
25.4 adds a `adventofcode run` command that removes the ugly boilerplate that you had to have in your puzzle files until now!
Before: After:
25.4 adds a `adventofcode run` command that removes the ugly boilerplate that you had to have in your puzzle files until now!
Before: After:
Day 2 of #adventofcode kinda felt easier than day 1 or was it just me?
I got to the solution fairly quickly but it was a bit slow. I then spent the next hour optimizing it and managed to make part 1 200x faster and part 2 500x faster 🎉
I got to the solution fairly quickly but it was a bit slow. I then spent the next hour optimizing it and managed to make part 1 200x faster and part 2 500x faster 🎉
December 2, 2025 at 7:11 AM
Day 2 of #adventofcode kinda felt easier than day 1 or was it just me?
I got to the solution fairly quickly but it was a bit slow. I then spent the next hour optimizing it and managed to make part 1 200x faster and part 2 500x faster 🎉
I got to the solution fairly quickly but it was a bit slow. I then spent the next hour optimizing it and managed to make part 1 200x faster and part 2 500x faster 🎉
Day 1 of #adventofcode felt a bit harder than previous day 1 puzzles. It took me way longer to figure out part 2 than I care to admit, but I'm blaming this on my sleepy brain 😅
My code took 1.1ms for both parts without any perf optimizations 🎉
Eleven more to go!
My code took 1.1ms for both parts without any perf optimizations 🎉
Eleven more to go!
December 1, 2025 at 4:10 PM
Day 1 of #adventofcode felt a bit harder than previous day 1 puzzles. It took me way longer to figure out part 2 than I care to admit, but I'm blaming this on my sleepy brain 😅
My code took 1.1ms for both parts without any perf optimizations 🎉
Eleven more to go!
My code took 1.1ms for both parts without any perf optimizations 🎉
Eleven more to go!
6 hours until the first advent of code puzzle unlocks. Who's going to participate this year? 🎄
November 30, 2025 at 11:02 PM
6 hours until the first advent of code puzzle unlocks. Who's going to participate this year? 🎄
I've just published a new version of my adventofcode PyPI package, just in time for Advent of Code that starts in 36 hours! 🎉
I've added a command line tool that helps you scaffold all the files for puzzle days because I got annoyed by copy pasting the same file each time!
pypi.org/project/adv...
I've added a command line tool that helps you scaffold all the files for puzzle days because I got annoyed by copy pasting the same file each time!
pypi.org/project/adv...
November 29, 2025 at 4:55 PM
I've just published a new version of my adventofcode PyPI package, just in time for Advent of Code that starts in 36 hours! 🎉
I've added a command line tool that helps you scaffold all the files for puzzle days because I got annoyed by copy pasting the same file each time!
pypi.org/project/adv...
I've added a command line tool that helps you scaffold all the files for puzzle days because I got annoyed by copy pasting the same file each time!
pypi.org/project/adv...
Reposted by Anže
Wooo, unanimous acceptance of 810!
Python is getting lazy imports!
So excited about this!
discuss.python.org/t/pep-810-ex...
Python is getting lazy imports!
So excited about this!
discuss.python.org/t/pep-810-ex...
PEP 810: Explicit lazy imports
Dear PEP 810 authors. The Steering Council is happy to unanimously[1] accept “PEP 810, Explicit lazy imports”. Congratulations! We appreciate the way you were able to build on and improve the previ...
discuss.python.org
November 3, 2025 at 4:36 PM
Wooo, unanimous acceptance of 810!
Python is getting lazy imports!
So excited about this!
discuss.python.org/t/pep-810-ex...
Python is getting lazy imports!
So excited about this!
discuss.python.org/t/pep-810-ex...
Reposted by Anže
Python 3.9 is officially EOL!
Congratulations to @lukasz.langa.pl on a wonderful run as release manager! 🖤
discuss.python.org/t/the-final-...
Congratulations to @lukasz.langa.pl on a wonderful run as release manager! 🖤
discuss.python.org/t/the-final-...
The final Python 3.9 security fix release is out!
Python 3.9.25 is available now! If you’re still using that, grab the sources and build the update as there’s some final fixes: Security (low severity) gh-136063: email.message: ensured linear comp...
discuss.python.org
October 31, 2025 at 8:05 PM
Python 3.9 is officially EOL!
Congratulations to @lukasz.langa.pl on a wonderful run as release manager! 🖤
discuss.python.org/t/the-final-...
Congratulations to @lukasz.langa.pl on a wonderful run as release manager! 🖤
discuss.python.org/t/the-final-...
Carlton's proposal to move Django to an annual release cycle makes all the sense.
The x.2 LTS releases always felt wrong to me since it has always been much easier and safer to upgrade each version rather than doing the LTS to LTS leap in one go.
buttondown.com/carlton/arc...
The x.2 LTS releases always felt wrong to me since it has always been much easier and safer to upgrade each version rather than doing the LTS to LTS leap in one go.
buttondown.com/carlton/arc...
An Annual Release Cycle for Django
A proposal for moving Django to an annual release cycle.
buttondown.com
October 31, 2025 at 12:00 PM
Carlton's proposal to move Django to an annual release cycle makes all the sense.
The x.2 LTS releases always felt wrong to me since it has always been much easier and safer to upgrade each version rather than doing the LTS to LTS leap in one go.
buttondown.com/carlton/arc...
The x.2 LTS releases always felt wrong to me since it has always been much easier and safer to upgrade each version rather than doing the LTS to LTS leap in one go.
buttondown.com/carlton/arc...
Reposted by Anže
Useful article by @anze3db.pecar.me.
Be cautious with your memory usage.
blog.pecar.me/django-bulk-...
#django #python
Be cautious with your memory usage.
blog.pecar.me/django-bulk-...
#django #python
Django bulk_update memory issue
Recently, I had to write a Django migration to update hundreds of thousands of database objects.
blog.pecar.me
October 30, 2025 at 8:35 AM
Useful article by @anze3db.pecar.me.
Be cautious with your memory usage.
blog.pecar.me/django-bulk-...
#django #python
Be cautious with your memory usage.
blog.pecar.me/django-bulk-...
#django #python
Reposted by Anže
Hearts at the PSF are full today from the responses about the recent grant turn down news we shared. All of your kind words of support & solidarity, as well as your donations & new memberships, mean the world to us. We're so grateful to be in community with each of you 💛🐍💙
TLDR; The PSF has made the decision to put our community and our shared diversity, equity, and inclusion values ahead of seeking $1.5M in new revenue. Please read and share. pyfound.blogspot.com/2025/10/NSF-...
🧵
🧵
The official home of the Python Programming Language
www.python.org
October 28, 2025 at 7:04 PM
Hearts at the PSF are full today from the responses about the recent grant turn down news we shared. All of your kind words of support & solidarity, as well as your donations & new memberships, mean the world to us. We're so grateful to be in community with each of you 💛🐍💙
Reposted by Anže
TLDR; The PSF has made the decision to put our community and our shared diversity, equity, and inclusion values ahead of seeking $1.5M in new revenue. Please read and share. pyfound.blogspot.com/2025/10/NSF-...
🧵
🧵
The official home of the Python Programming Language
www.python.org
October 27, 2025 at 2:47 PM
TLDR; The PSF has made the decision to put our community and our shared diversity, equity, and inclusion values ahead of seeking $1.5M in new revenue. Please read and share. pyfound.blogspot.com/2025/10/NSF-...
🧵
🧵
us-east-1 is down, happy Monday!
October 20, 2025 at 8:55 AM
us-east-1 is down, happy Monday!
I had a memory issue with Django's bulk_update queryset method.
The TLDR version is that bulk_update prepares all the update statements in advance (even when batch_size is set) which can use more memory than expected.
Details and a solution in the blog:
blog.pecar.me/django-bulk...
The TLDR version is that bulk_update prepares all the update statements in advance (even when batch_size is set) which can use more memory than expected.
Details and a solution in the blog:
blog.pecar.me/django-bulk...
Django bulk_update memory issue
Recently, I had to write a Django migration to update hundreds of thousands of database objects. With some paper-napkin math I calculated that I can fit all the necessary data in memory, making the migration much simpler than it would have been otherwise.
blog.pecar.me
October 13, 2025 at 9:57 AM
I had a memory issue with Django's bulk_update queryset method.
The TLDR version is that bulk_update prepares all the update statements in advance (even when batch_size is set) which can use more memory than expected.
Details and a solution in the blog:
blog.pecar.me/django-bulk...
The TLDR version is that bulk_update prepares all the update statements in advance (even when batch_size is set) which can use more memory than expected.
Details and a solution in the blog:
blog.pecar.me/django-bulk...
Reposted by Anže
In case you prefer text over video, the blog post version of my #EuroPython keynote about why it took 4 years to get a lock files specification for #Python is now up at snarky.ca/why-it-took-... .
Why it took 4 years to get a lock files specification
(This is the blog post version of my keynote from EuroPython 2025 in Prague, Czechia.)
We now have a lock file format specification. That might not sound like a big deal, but for me it took 4 years o...
snarky.ca
October 11, 2025 at 3:48 AM
In case you prefer text over video, the blog post version of my #EuroPython keynote about why it took 4 years to get a lock files specification for #Python is now up at snarky.ca/why-it-took-... .
I've improved the performance of the starter packs list query from about 200ms to 2ms. 🎉
The trick was to stop dynamically computing the number of accounts in a starter pack and instead precompute it in a column.
A bit more work on each update, but worth it!
The trick was to stop dynamically computing the number of accounts in a starter pack and instead precompute it in a column.
A bit more work on each update, but worth it!
October 11, 2025 at 9:23 AM
I've improved the performance of the starter packs list query from about 200ms to 2ms. 🎉
The trick was to stop dynamically computing the number of accounts in a starter pack and instead precompute it in a column.
A bit more work on each update, but worth it!
The trick was to stop dynamically computing the number of accounts in a starter pack and instead precompute it in a column.
A bit more work on each update, but worth it!
Yesterday, Python 3.14 was released, and today all of my Django side projects are running on 3.14. 🎉
The upgrade didn't require any code changes on my part, but I did see a few return statements in the finally block SyntaxWarnings in a few dependencies.
The upgrade didn't require any code changes on my part, but I did see a few return statements in the finally block SyntaxWarnings in a few dependencies.
October 8, 2025 at 8:49 AM
Yesterday, Python 3.14 was released, and today all of my Django side projects are running on 3.14. 🎉
The upgrade didn't require any code changes on my part, but I did see a few return statements in the finally block SyntaxWarnings in a few dependencies.
The upgrade didn't require any code changes on my part, but I did see a few return statements in the finally block SyntaxWarnings in a few dependencies.
Reposted by Anže
🐍 Python 3.14 is here! 🎉
✨ Template strings (t-strings) for safer string interpolation
🚀 Free-threaded Python officially supported (bye GIL!)
🎨 Syntax highlighting in the REPL
📦 Zstandard compression in stdlib
🔍 Remote PDB debugging
Full release notes: docs.python.org/3.14/whatsne...
✨ Template strings (t-strings) for safer string interpolation
🚀 Free-threaded Python officially supported (bye GIL!)
🎨 Syntax highlighting in the REPL
📦 Zstandard compression in stdlib
🔍 Remote PDB debugging
Full release notes: docs.python.org/3.14/whatsne...
October 7, 2025 at 4:46 PM
🐍 Python 3.14 is here! 🎉
✨ Template strings (t-strings) for safer string interpolation
🚀 Free-threaded Python officially supported (bye GIL!)
🎨 Syntax highlighting in the REPL
📦 Zstandard compression in stdlib
🔍 Remote PDB debugging
Full release notes: docs.python.org/3.14/whatsne...
✨ Template strings (t-strings) for safer string interpolation
🚀 Free-threaded Python officially supported (bye GIL!)
🎨 Syntax highlighting in the REPL
📦 Zstandard compression in stdlib
🔍 Remote PDB debugging
Full release notes: docs.python.org/3.14/whatsne...
I was moving imports into functions just last week and thinking how horrible this is. Great that we’ll get a solution for this in 3.15! 🤞🤞🎉🎉
Let me post a *non*-subskeet for once... We made a thing!
discuss.python.org/t/pep-810-ex...
#Python #PEP
discuss.python.org/t/pep-810-ex...
#Python #PEP
PEP 810: Explicit lazy imports
👋 Hi everyone, We are very exited to share with you PEP 810: Explicit lazy imports: We’re proposing an opt-in lazy import syntax that defers module loading until first use, aiming for faster startup,...
discuss.python.org
October 3, 2025 at 10:16 PM
I was moving imports into functions just last week and thinking how horrible this is. Great that we’ll get a solution for this in 3.15! 🤞🤞🎉🎉