articles/2024/trying-pdm/

[giscus[bot]]

articles/2024/trying-pdm/

After comparing uv to Poetry, I am trying out PDM. On paper it combines all the best things of Poetry and uv, without their downsides. How does it hold up?

https://www.loopwerk.io/articles/2024/trying-pdm/

[schneebuzz]

Thanks for the write up! It really helps as I am currently evaluating the use of PDM vs Poetry.

One thing I was wondering about, you state:

Poetry does this a hundred times better by its add command not immediately installing packages.

This seems not true, the add command, as documented, Adds a new dependency to pyproject.toml and installs it..
Am I missing something here?

Also, did you compare the editable installs feature of poetry vs. PDM and if so, what are your thoughts?
We are currently using a lot of "in-project-packages" that we install as editable. In PDM, those must go into a "dev" dependency group as PDM does not allow editable installs of prod dependencies.

[kevinrenskers]

Which version of Poetry are you running? I'm running 1.8.3, which is the latest.

And my pyproject.toml file looks like this;

[tool.poetry]
name = "my-project-name"
version = "0.1.0"
description = ""
readme = "readme.md"
package-mode = false

[tool.poetry.dependencies]
python = "^3.12"
Django = "^5.0.1"

[tool.poetry.group.dev]
optional = true

[tool.poetry.group.dev.dependencies]
ruff = "^0.6.0"

[tool.poetry.group.prod]
optional = true

[tool.poetry.group.prod.dependencies]
gunicorn = "^23.0.0"

[build-system]
requires = ["poetry-core"]
build-backend = "poetry.core.masonry.api"

I'm guessing your dev group is set up differently.

[schneebuzz]

Oh, I completely overlooked the fact that dependency groups are not optional by default. I am also using the latest versions for both PDM and poetry.

FYI: I found that pdm add has the --no-sync option, which makes PDM only modify the toml without installing the package.

Would you mind sharing the pyproject.toml for the PDM example as I am not able to reproduce the failing removal of dependencies. Anyway PDM also does not claim that it removes any dependency in my setup when installing only a specific group.

[kevinrenskers]

FYI: I found that pdm add has the --no-sync option, which makes PDM only modify the toml without installing the package.

Oh, that's great! That would solve one of the major downsides I had with PDM. I'll give this a go and update the article if this indeed solves it.

Would you mind sharing the pyproject.toml for the PDM example

[project]
name = "pdm-test"
version = "0.1.0"
description = "Default template for PDM package"
dependencies = [
    "django>=5.1.1",
]
requires-python = "==3.12.*"
readme = "README.md"
license = {text = "MIT"}

[project.optional-dependencies]
dev = [
    "ruff>=0.6.9",
]
prod = [
    "gunicorn>=23.0.0",
]

[tool.pdm]
distribution = false

[aureliojargas]

Nice writeup! This article and the "Poetry versus uv". Being a dissatisfied Poetry user myself, I'm having similar doubts on what tool to use.

Since uv is in a fast development cycle, I think your two concerns from the Conclusion were already addressed.

And when it comes to handling optional dependency groups:

• uv doesn’t have the concept of multiple dependency groups at all

In 2024-10-25 uv have added support for dependency groups (following PEP 735): https://github.com/astral-sh/uv/releases/tag/0.4.27

Finding and updating outdated packages:

• uv fails by not making it possible to see outdated packages

This was just merged 4 days ago:

• Add support for pip list --outdated
• Add uv tree --outdated

And released 3 days ago in https://github.com/astral-sh/uv/releases/tag/0.5.0

[kevinrenskers]

Ah, thanks for the heads-up! That's great to hear, I'll definitely try that out and update the article if necessary.

[kevinrenskers]

All my biggest gripes have indeed been solved and I will definitely move my projects from Poetry to uv. New article: https://www.loopwerk.io/articles/2024/python-uv-revisited/.

[frostming]

Regarding the issue of selecting the Python interpreter for PDM, I am using version 2.21.0 and cannot reproduce. It's possible that the bug has already been fixed?

[kevinrenskers]

Are you using uv as the resolver? I only had the problem when that was the case. But yeah maybe it's solved now, no idea.

[frostming]

Yes using uv

[kevinrenskers]

I used whatever PDM version was the latest version at the time of writing this article, so October 4th. Next time I write an article like this I'll note the versions used.