Posts tagged: python

I’ve been playing with 3d printing some items through the slant3d api. I’ve been pricing out different prints by running a slice request through their api.

I’ve been using uv for project management. It’s been working well for quick projects like this while making it reproducible, I’m still all in on hatch for libraries.

mkdir slantproject cd slantproject uv init uv venv . ./.venv/bin/activate uv add httpx rich python-dotenv

Get an api key #

You will need an api key from the slant api, which currently requires a google account and a credit card to create.

# .env # replace with your api key from https://api-fe-two.vercel.app/ SLANT_API_KEY=sl-**

slicing an stl with teh slant api #

Then you can run the python script to price out your print. I’m not exactly sure how this compares to an order, especially when you add in different materials.

Hynek has a sick dockerfile setup for using uv in python projects.

SQLModel models ship with an is_, and is_not that you can use to compare to None without pesky linters complaining.

This comment summed it up quite well.

I believe this is concerned entirely with SQLAlchemy, not with SQLModel, and has to do with the required semantics to construct a BinaryExpression object. Hero.age == None evaluates to a BinaryExpression object which is eventually used to construct the SQL query that the SQLAlchemy engine issues to your DBMS. Hero.age is None evaluates to False immediately, and not a BinaryExpression, which short-circuits the query no matter the value of age in a row. From a cursory search, it does not seem that the is operator can be overridden in Python. This could help explain why the only possibility is by using the == operator, which can be overridden.

so rather than using Team.heros == None we can use Team.seros.is_(None) which checks for itentity not equality.

Today I learned that you cannot pass negative integers as values to typer. in this case context_settings={"ignore_unknown_options": True} is required so that the - does not look like a flag.

This new demo of textual is wildly awesome, so many widgets and features being added into the main library. The themes and animations are on point and far surpass my expectations of a tui.

weazyprint was throwing me some errors, turns out that it’s currently not compatible with the latest pydyf package.

my error

TypeError: __init__() takes 1 positional argument but 3 were give

I fixed it by locking in pydyf at 0.8.0

uv now can install python for you. uv is inspired by rust’s cargo, an all in one fast package and installation manager. uv is so fast and becoming feature complete, it’s really changing the python packaging ecosystem.

Hard to argue this take, happy to see that its at the top. With it being such an old language its amazing that it still holds this position, and not surprising that it has warts, and thing that have turn users off from wanting anything to do with it.

timestamped in the link

markdown it py running in rust claims to be 20x faster. I’ll definitely look into this if markdown it py is ever a bottleneck in my performance. At first glance it appears that plugins are written in rust not python, and there is no admonition plugin, so I’ll keep my eye on it for now, but I can’t use it.

diskcache has a peekitem method that allows you to lookup the expire_time of a cached item without changing it. I recently used this to implement debounce for fastapi background tasks with multiple workers running. since all the workers I care about are on the same machine, but running in different processes diskcache was a great option. All workers have access to the same disk, but not the same variables in memory.

I’ve been using fastapi more and more lately and one feature I just started using is background tasks [[ thoughts-333 ]].

I am using it for longer running tasks and I don’t want to give users the ability to spam these long running tasks with many duplicates running at the same time. And each fastapi worker will be running in a different process so I cannot keep track of work in memory, I have to do it in a distributed fashion. Since they are all running on the same machine with access to the same disk, diskcache is a good choice

My brain first went to thinking I needed another service like redis running alongside fastapi for this, then it hit me that I can use diskcache.

Here is how I used diskcache to debounce taking screenshots for a unique shot every 60 seconds.

pyannotate is a tool that uses runtime types to suggest type annotations to use. Test runners such as pytest can be used to generate the types.

Create virtual environments for any Python version, without needing Python installed.

Great listen for anyone interested in productionizing python code with docker. Itamar brings up some

Don’t trust base images for security, upgrade your packages. Vulnerabilties become published and solved giving the bad guys istructions how to wreck your day and these fixes wont come to your docker application for up to two weeks due to image build tatency.

For job based containers pre-compile your pyc for faster startup.

Alpine linux is probably not what you want for python. Many packages such as postgres ship pre-copiled binaries that work for most linux distributions wich use glibc, but alpine uses musl so the binaries will be incompatable requiring you to need to install a bunch of build dependencies.

xxHash is an extremely fast non-cryptographic hash algorithm, working at RAM speed limit. It is proposed in four flavors (XXH32, XXH64, XXH3_64bits and XXH3_128bits). The latest variant, XXH3, offers improved performance across the board, especially on small data.

I hit an issue with markata where even though a bunch of articles were cached, the site build was still slow because I was hitting hashlib.sha256 so hard for cache keys. I was shocked when this popped up in my profiler as a significant portion of the time spent. I swapped out for xxhash and that issue completely went away.

I just implemented a latest blog post link in Markata by asking for the first post slug from the blog feed. The implementation uses the jinja_md plugin to render jinja against the markdown and a tag to redirect.

My latest blog post is [[ {{ markata.feeds.blog.posts[0].slug }} ]]. Click the link if you are not automatically redirected. <meta http-equiv="Refresh" content="0; url='/{{ markata.feeds.blog.posts[0].slug }}'" />

Setting up the feed #

Feeds are setup in markata.toml configuration. They provide a handy way to create an html feed, rss feed, and quickly reference a filtered set of posts like this.

# you will need to enable the jinja_md plugin along with the defaults [markata] hooks = [ "markata.plugins.jinja_md", "default", ] # set up the blog feed [[markata.feeds]] slug = 'blog'...