adhoc-python/flake.nix

{
  description = "Flake utils demo";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    pre-commit-hooks.url = "github:cachix/pre-commit-hooks.nix";
  };

  outputs = { self, nixpkgs, flake-utils, pre-commit-hooks }:
    flake-utils.lib.eachDefaultSystem
      (system:
        let
          pkgs = nixpkgs.legacyPackages.${system};
          minVersion = 8;
          maxVersion = 11;
          mkPython = version: "python3${toString version}";
          pythonVersions = map mkPython (pkgs.lib.lists.range minVersion maxVersion);
          mkDevShell = version: pkgs.mkShell {
            buildInputs = [ pkgs.${version} pkgs.poetry ];
          };
          addPreCommit = shell: shell.overrideAttrs (old: {
            inherit (self.checks.${system}.pre-commit-check) shellHook;
          });
          devShells = pkgs.lib.genAttrs pythonVersions mkDevShell;
          preCommitShells = pkgs.lib.mapAttrs' (name: value: pkgs.lib.nameValuePair (name + "-precommit") (addPreCommit value)) devShells;
          allShells = devShells // preCommitShells;
        in
        {
          devShells = allShells // {
            default = self.devShells.${system}."${mkPython maxVersion}-precommit";
          };
          checks.pre-commit-check = pre-commit-hooks.lib."${system}".run {
            src = ./.;
            hooks = {
              nixpkgs-fmt.enable = true;
              statix.enable = true;
              shellcheck.enable = true;
              black.enable = true;
              isort.enable = true;
            };
          };
        }) // {
      templates.default = {
        path = ./.;
        description = "A adhoc python environment";
      };
    };
}