python2nix.sh

#!/usr/bin/env bash
#
#  Usage
#
#     python2nix my_pypi_package > my_package.nix
#
#  TODO
#    - accept 'format' as arg
#    - prepopulate dependencies?
set -euo pipefail

tmpfile=$(mktemp)
#pname="$(echo $1 | tr '-' '_')"
pname="$1"
version=$(
    curl -sG -H 'Host: pypi.org' -H 'Accept: application/json' \
        https://pypi.org/pypi/$1/json | \
        jq ".releases | keys | last")

>&2 echo "Found version $version"

cat > $tmpfile <<EOF
with import <nixpkgs> {};
with python3Packages;

buildPythonPackage rec {

  pname = "$pname";
  version = $version;

  src = fetchPypi {
    inherit pname version;
    sha256 = "XXX";
  };
}
EOF

SHA=$(nix-prefetch-url --unpack -A src $tmpfile)
rm $tmpfile

cat <<EOF
{ buildPythonPackage
, fetchPypi
}:

buildPythonPackage rec {

  pname = "$pname";
  version = $version;

  src = fetchPypi {
    inherit pname version;
    sha256 = "$SHA";
  };

  propagatedBuildInputs = [
  ];
}
EOF