PEP 735 what is it’s goal? Does it solve our dependency hell issue?
A deep dive and out comes this limitation
The mutual compatibility of Dependency Groups is not guaranteed.
– https://peps.python.org/pep-0735/#lockfile-generation
Huh?! Why not?
mutual compatibility or go pound sand!
pip install -r requirements/dev.lock
pip install -r requirements/kit.lock -r requirements/manage.lock
The above code, purposefully, does not afford pip a fighting chance. If there are incompatibilities, it’ll come out when trying randomized combinations.
Without a means to test for and guarantee mutual compatibility, end users will always find themselves in dependency hell.
Any combination of requirement files (or dependency groups), intended for the same venv, MUST always work!
What if this is scaled further, instead of one package, a chain of packages?!
Throwing out an alternative. Not making the assumption that more TOML is better. Cuz the contents of those
requirements.txtfiles are rw, not ro. I seepyproject.tomlas a ro configuration file.Do you agree or should
pyproject.tomlbe rw?Another option, strictly validated YAML.
For the configuration section, before parsing occurs, strict validation occurs against a schema.
TOML vs strictyaml – https://hitchdev.com/strictyaml/why-not/toml/
I didn’t know about StrictYAML, we’re really going in circles lol
TOML is already RW by Poetry, PDM, and uv.
Yeah, but should it be (rw)?
If it’s rw, it’s a database, not a config file.
No software designer thinks … postgreSQL, sqlite, mariadb, duckdb, … nah TOML
Or at least yaml turns out to be not a strange suggestion
it’s a config file that should be readable and writeable by both humans and tools. So yeah, it makes sense.
And I don’t lile yaml personally, so that’s a plus to me. My pet peeve is never knowing what names before a colon are part of the schema and which ones are user-defined. Even with strictyaml, reading the nesting only through indentation is harder than in toml.
You are not wrong, yaml can be confusing.
Recently got tripped up on sequence of mapping of mapping. Which is just a simple list of records.
But for the life of me, couldn’t get a simple example working.
Ended up reversed the logic.
Instead of parsing a yaml str. Created the sample list of dict and asked strictyaml to produce the yaml str.
Turns out the record is indented four spaces, not two.
- file: "great_file_name_0.yml" key_0: "value 0" - file: "great_file_name_1.yml" key_0: "value 0"Something like ^^. That is a yaml database. It has records, a schema, and can be safely validated!
The strictyaml documentation covers ridiculously simple cases. There are no practical examples. So it was no help.
Parser kept complaining about duplicate keys.
uh… a database implies use of a database management system. I don’t think saying that a YAML/TOML/JSON/whatever file is a database is very useful, as these files are usually created and modified without any guarantees.
It’s not even about being incorrect, it’s just not that useful.
But it’s treated 100% like a crappy CRUD database with no modern features or SQL
it’s a file containing records with a strict schema. And nothing else
You have a strange definition of “database”. Almost every language I touch on a daily basis (JS, Rust, C#) uses their package meta file to declare dependencies as well, yet none of those languages treat it as a “database”.
In this super specific case, the data that is being worked with is a many list of dict. A schema-less table. There would be frequent updates to this data. As package versions are upgraded, fixes are made, and security patches are added.
It seems you’re describing a lock file. No one is proposing to use or currently using pyproject.toml as a lock file. And even lock files have well defined schemas, not just an arbitrary JSON-like object.
There’s a few edge cases on parsing dependency urls. So it’s not completely black and white.
just have to read over to pip-compile-multi to see that. (i have high praise for that project don’t get me wrong)
then i’m misunderstanding what data
dependencies groupsare supposed to be storing. Just the equivalent of requirements.in files and mapping that to a target? And no-c(constraints) support?!Feels like tying one of hands behind our back.
see https://packaging.python.org/en/latest/specifications/dependency-groups/#dependency-groups
It’s not schemaless at all, it’s a dictionary of string to string. Not that complex.
The strictyaml schema holds a pinch of nuance.
The value argument is automagically coersed to a str. Which is nice; since the field value can be either integer or str. And i want a str, not an int.
A Rust solution would be superior, but the Python API is reasonable; not bad at all.
I’m not sure what you’re talking about. My point was that dependency definitions in pyproject.toml aren’t schemaless.
strict schema and a spec are not the same. package pyproject-validate can check if a pyproject.toml follows the spec, but not be using a strict schema.
A schema is similar to using Rust. Every element is strictly typed. Is that an int or a str is not enforced by a spec
If there was a strict schema, package pyproject-validate would be unnecessary
especially JS, some packages.json are super long. The sqlite author would blush looking at that
Sure, but why is that a bad thing when you have lots of direct dependencies?
As the quantity and relationships complexity increases so to does the need for management tools to deal with the chaos.
Most Python coders cope by keeping things overly simple. Avoiding complexity at all costs.
Do you fully embrace requirement file complexity or do you avoid it?
assume one venv
has no way to deal with unavoidable incompatibilities
Which maybe due to: a package becoming unmaintained or overly zealous limiting allowed versions
has no way to adapt to security vulnerabilities (e.g. CVE-2024-9287)
has no intelligent way to normalize both direct and transitive dependency versions across lock files
Not in circles, this is helping for me.
If you have strong support for a rw toml, would like to hear your arguments
Highly suggest reading the strictyaml docs
The author lays out both
Why
Why not
Should be required reading for anyone dealing with config files, especially those encountering yaml.
Warning: After reading these, and confirming the examples yourself, seeing packages using pyyaml will come off as lessor