add poetry2nix post for real

site/content/posts/poetry2nix-development-flake-with-matplotlib-gtk-support.md

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+title = "Poetry2Nix Development Flake with Matplotlib GTK Support"
+author = ["Valentin Boettcher"]
+date = 2024-05-11T17:57:00-04:00
+categories = ["Hacks"]
+draft = false
++++
+
+I recently had the pleasure to dive back into python for work. In the
+past, I was happily using `org-babel` notebooks through
+[emacs-jupyter](https://github.com/nnicandro/emacs-jupyter). However, I have since switched to a more REPL/script
+driven workflow as I find that programming notebooks require a great
+deal of discipline to not end up as a horrible mess. For my new
+workflow, I need interactive plotting to work.
+
+So let's get straight to the meat. The following `Flake` dives you a
+development shell that tries to replicate the underlying [poetry](https://python-poetry.org/)
+project in full nix using [poetry2nix](https://github.com/nix-community/poetry2nix).
+
+```nix
+{
+  description = "[your description]";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable-small";
+    poetry2nix = {
+      url = "github:vale981/nix-community/poetry2nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = inputs @ { self, nixpkgs, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        poetry2nix = inputs.poetry2nix.lib.mkPoetry2Nix { inherit pkgs; };
+      in
+      {
+        packages = {
+          yourPackage = poetry2nix.mkPoetryApplication {
+            projectDir = self;
+
+            # set this to true to use premade wheels rather than the source
+            preferWheels = false;
+
+            # this enables interactive plotting support with GTK
+            overrides = poetry2nix.overrides.withDefaults (final: prev: {
+              matplotlib = with pkgs; prev.matplotlib.overridePythonAttrs (
+                old:
+                {
+                  passthru.args.enableGtk3 = true;
+                }
+              );
+            });
+          };
+          default = self.packages.${system}.yourPackage;
+        };
+
+        # Shell for app dependencies.
+        #
+        #     nix develop
+        #
+        # Use this shell for developing your app.
+        devShells.default = pkgs.mkShell {
+          inputsFrom = [ self.packages.${system}.yourPackage ];
+          package = with pkgs; [
+            # any development dependencies that you might have in nixpkgs
+            ruff
+            pyright
+          ];
+        };
+
+        # Shell for poetry.
+        #
+        #     nix develop .#poetry
+        #
+        # Use this shell for changes to pyproject.toml and poetry.lock.
+        devShells.poetry = pkgs.mkShell {
+          packages = [ pkgs.poetry ];
+        };
+      });
+}
+```
+
+The workflow is as follows. Running `nix develop .#poetry` will give you
+a shell with poetry available. You can then `poetry init` and `poetry add`
+and `poetry lock` (not install) to your hearts content. A plain `nix
+develop` will then set up the environment according to the `poetry.lock`
+that poetry generates. Note that [this pull request](https://github.com/nix-community/poetry2nix/pull/1651) has to be resolved
+before the above works with `preferWheels = true`.
+
+You might want to checkout [direnv](https://direnv.net/) and [nix-direnv](https://github.com/nix-community/nix-direnv) for added convenience.