When building complex readable strings, consider building them out of smaller fragments. The function `oxford_comma`, shown below, demonstrates this technique. What's the point of the smaller fragments?

Python has a very well-known naming convention: Names that start with a leading underscore are “private”. This means the outside world has no business using them. E.g., attributes and methods starting with `_` in a class mean they're for that class only.

I'm really enjoying this idea I stole from Simon Willison I now have a `tools` subdomain where I host small HTML+JS tools built with LLMs that help me with whatever random things I need. E.g., I have one that pre-fills my testimonial form and generates a URL I can share easily!

The methods `strftime` and `strptime` can be used to convert dates/times into strings and vice-versa. Here's a mnemonic to help you: 👉 `strptime` has a “P” for “Parse date/time”, so string -> date 👉 `strftime` has an “F” for “Format date/time”, so date -> string

A generator, duck typing, and a branchless conditional walk into a bar... You can read the rest of this Python joke here 👉 mathspp.com/blog/a-gene...

The string method `str.split` has a parameter `maxsplit` that determines the maximum number of splits that will be performed. The returned list with the splits (and possibly the remainder of the string) has a maximum length of `maxsplit + 1`.

Yesterday's training culminated with creating a couple of projects (with uv). We then uploaded them to (Test) PyPI and we got people to install each other's apps and run them on their own computers. It was clearly a moment of *fun* for folks involved. 🤩

This is your friendly reminder that str.split accepts a parameter to determine the maximum number of splits. You get up to n splits and the remainder of the string.

Days 2 and 3 were a success, if I might say so myself. The grounded, fundamental approach to OOP resonated well with the participants. Even those who already knew OOP said they learned a lot by starting with the fundamentals! What a surprise! (Not...)

Live-coding during trainings + automatically syncing to git so everyone has access to what I'm typing = Very informative git history.

Yesterday went well. Today I'm teaching OOP from the ground up. But like, REALLY from the ground up. Not just “you write class Something then __init__ and `self` is the first argument because reasons”. Might turn this into a chapter for my book “Pydon'ts”, actually...

Python is for everyone ❤️. Become a PSF member if you can!

There's nothing quite like the excitement of being about to start a week-long Python training. Being this excited about my job feels illegal 🤣

Believe it or not, it took me 30+ min and nagging a core dev to get this TINY documentation issue fixed. But at least I'll sleep well tonight, knowing all “See also” call outs are correctly formatted.

strptime vs strftime strPtime has the P for “parse time” So it'll accept a string and Parse a time from it. strFtime has the F for “from time” or “format time” So it'll accept a time/date/datetime and Format it as a string. You're welcome 🤗

Yesterday I was reading the “What's new in Python 3.14” doc page. Not just the headlines; I was reading the whole document. (Looking for ideas for Python tips to share in my newsletter.) And damn... The community and the core devs are on fire!

I'd just like to reiterate the honour it is to receive this award and I'm deeply humbled by the fact that all the other recipients (Katie, Sarah, and past recipients) have made such meaningful contributions to the community and yet I'm among them! This is just the start :D

There's just SO MUCH STUFF in Python 3.14. ✨ I decided I'm going to share the new updates, drop by drop, in my Python drops 🐍💧 newsletter. If you want to learn about what's new in Python 3.14 without getting overwhelmed, subscribe 👉 mathspp.com/drops

Maybe it's too early, but I'm having a hard time understanding the difference between `pathlib.Path.move` (new in Python 3.14) and `pathlib.Path.rename`. Maybe the edge cases are different, but isn't the “main behaviour” the same?

I've turned this blog post cheatsheet into a downloadable cheatsheet. You can get the cheatsheet from here: mathspp.com/blog/uv-chea...

This was in my drafts for almost a year. It's published now. mathspp.com/blog/pydonts...

I'm writing an email about how vegetarian lions relate to dataclasses. If you subscribe quickly enough, you'll also get it. (If you don't get it and you want to read it, reply to the welcome email and I'll forward it to you.) Subscribe here 👉 mathspp.com/insider

Is this looking good? (I'm turning my “uv cheatsheet” blog post into an actual cheatsheet you can download.)

Today I learned that around 4500 thousand years ago Egyptians already had 30 different types of bread. I can't name 30 types of bread right now!

I only started using the word “yield” in my spoken and written English after learning about generators in Python! 🐍

Yesterday was the last day of the intermediate Python course cohort and we talked about packaging. Folks were having so much fun using @crmarsh.com's uv to manage their toy projects and to package & publish them! To share the joys of uv with even more people, I created a small uv cheatsheet:

Here's a fun way of counting words in a string in Python. This doesn't split the string then count, so it'll work for ridiculously large strings (e.g. files you can't load into memory) Plus, I had fun making it branchless (i.e., without explicit `if`s) by doing arithmetic with the flag `in_word` 😅

Do you want to create professional-looking projects? You'll need lots of shiny badges like the one you can see below for my most recent project 👇 You can create custom badges at shields.io, it's a pretty cool service! Very professional, much wow!

Everything you need to know about `functools.partial`: 👉 what it's for 👉 how to use it 👉 code examples And even how to use it with `functools.Placeholder`, a new 3.14 feature. youtu.be/LE66sVEMbi8

I am happy to report that I didn't blunder anything today.

OK FINALLY I RECORDED IT But now I have day 2 of the cohort, so I'll publish later!

It always gets me when I write :D in a GitHub issue and the emoji dropdown suggests a dagger 🤣

Just got out from the 1st live session of this week's intermediate Python course. The only thing I messed up was that I only remembered that I should be recording when I was ~10 min into the content 🤦 Otherwise it's going well :D

A good example of what `functools.Placeholder` from Python 3.14 allows.

Today I did a couple of false starts but today I'm publishing a video about `functools.partial` and the new Python 3.14 update. What's something you don't understand about `functools.partial` that you wish I explained?

I think it's brilliant that PyPI has TestPyPI for you to test your packaging tools and workflows without messing up with the real index. Do other languages have this?

Ok, so I tried out the ChatGPT agent to try to restructure a part of my website. After 20-25 minutes it says it's done moving some files around but it created a zip of the new files that I can't access 🤷 I don't know how to access the work produced 🤣

It's starting in less than 60 seconds! 😱

I am now a poet. ✍️

The Python documentary premiers today! (In roughly 6 hours.) I'm looking forward to watching this documentary about the origin of Python and its evolution through the past ~35 (?) years! Starring plenty of influential Python people, of which Guido is just one! 🎥 www.youtube.com/watch?v=GfH4...

I'm working on a Ruff-related video course for @realpython.com ... As my reviewer noted, my poor (or genius?) choice of directory name makes it look like my terminal is barking all the time 🤣 What do you say? Poor choice for a directory name or genius move?

For the past 25 weeks, I've sent a drop of Python knowledge to my Python drops 🐍💧 newsletter. A short & actionable tip: 👉 a method you didn't know 👉 an idiom combining 2+ functions 👉 or something else entirely I send 5 per week. (One per business day.) Some weeks, I have 20 ideas. But!

The Python module `operator` provides both `add` and `concat`. `add` works with numbers, obviously... But also the lists/strings/etc that you concatenate with the plus sign `+`. So, why is there `concat`? It's not a trick Q; I have no idea.

What are your favourite context managers in Python?

The names we give to things are important. For example, `itertools.batched` is there. It's easy to understand. You can use it to batch stuff. E.g., batch data for API calls. But suddenly, if you call it `paginated = batched`, it's OBVIOUS you can use it to paginate stuff. Now, it's not about 1/n

To read markdown directly from your terminal: ``` uvx frogmouth README.md ``` A markdown browser written in Python (with Textual). Pretty cool! github.com/textualize/f...

uv 0.8.13 now comes with `uv format`! I think making Ruff accessible from the uv interface makes a lot of sense. I've installed Ruff 2 or 3 days ago but I've been using uv for months. If `uv format` were a thing already, I would've started using Ruff much earlier! mathspp.com/blog/til/for...

pycon (US) recap just dropped! pycon.blogspot.com/2025/08/pyco... 🐍🎉

I just had a couple of minutes of fun writing an infinite binary counter in Python. However, I thought I'd be able to express this easily with recursion but nothing obvious comes to mind... Any suggestions?

Can someone help me? Where do I even start understanding what's going on? 🤣 How do I use the scaffolding in that link to show, for example, that three isn't equal to two? Or can I not do that with what's already there?