a

.gitignore

result
*.bsp

flake.lock

{
  "nodes": {
    "nixpkgs": {
      "locked": {
        "lastModified": 1701336116,
        "narHash": "sha256-kEmpezCR/FpITc6yMbAh4WrOCiT2zg5pSjnKrq51h5Y=",
        "owner": "NixOS",
        "repo": "nixpkgs",
        "rev": "f5c27c6136db4d76c30e533c20517df6864c46ee",
        "type": "github"
      },
      "original": {
        "id": "nixpkgs",
        "type": "indirect"
      }
    },
    "root": {
      "inputs": {
        "nixpkgs": "nixpkgs"
      }
    }
  },
  "root": "root",
  "version": 7
}

flake.nix

{
  description = "A very basic flake";

  outputs = { self, nixpkgs }: 
  let
    system = "x86_64-linux";
    pkgs = import nixpkgs { inherit system; };
    pyp = pkgs.python311Packages;
  in {
    packages.x86_64-linux.default = pyp.buildPythonApplication {
      name = "skynix";
      pyproject = true;
      nativeBuildInputs = [ pyp.hatchling ];
      propagatedBuildInputs = [ pyp.skyfield ];
      src = self;
    };
    devShells.${system}.default = pkgs.mkShell {
      packages = [
        (pkgs.python311.withPackages (ps: [ ps.skyfield ]))
      ];
      shellHook = "exec python";
    };

  };
}

pyproject.toml

[project]
name = "skynix"
version = "0.1.0"
dependencies = ["skyfield"]
requires-python = ">=3.9"

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[project.scripts]
skynix = "skynix:main"

skynix.py

#!/usr/bin/env python
import skyfield
from skyfield.api import Topos, load

def main():
    ts = load.timescale()
    planets = load('de421.bsp')
    sun = planets['sun']
    earth = planets['earth']
    np = earth + Topos('34 N', '139 W')
    t = ts.utc(2023, 12, 21, 12 + 9, 15, 0)
    print(np.at(t).observe(sun).apparent().altaz())