fix ruff checks (mostly documentation and dead code)

flupdt/flake_show.py

@@ -1,11 +1,10 @@
-#!/usr/bin/env python3
+"""Utility to extract flake output info using nix flake (show|check)."""
 
 import json
 import logging
 import re
 import shutil
 import typing
-from subprocess import Popen
 
 from flupdt.common import bash_wrapper
 
@@ -16,6 +15,12 @@ output_regexes = [
 
 
 def traverse_json_base(json_dict: dict[str, typing.Any], path: list[str]) -> list[str]:
+    """Crawls through the flake outputs to get nixos-configuration and derivation types.
+
+    :param json_dict: dict of flake outputs to check
+    :param path: a list of outputs constructed so far
+    :returns the output path list, plus any new paths found
+    """
     final_paths = []
     for key, value in json_dict.items():
         if isinstance(value, dict):
@@ -32,10 +37,21 @@ def traverse_json_base(json_dict: dict[str, typing.Any], path: list[str]) -> lis
 
 
 def traverse_json(json_dict: dict) -> list[str]:
+    """Crawls through the flake outputs to get nixos-configuration and derivation types.
+
+    :param json_dict: dict of flake outputs to check
+    :returns a list of outputs that can be evaluated
+    """
     return traverse_json_base(json_dict, [])
 
 
 def get_derivations_from_check(nix_path: str, path_to_flake: str) -> list[str]:
+    """Gets all derivations in a flake, using check instead of show.
+
+    :param nix_path: path to nix binary
+    :param path_to_flake: path to flake to be checked
+    :returns a list of all valid derivations in the flake
+    """
     flake_check = bash_wrapper(f"{nix_path} flake check --verbose --keep-going", path=path_to_flake)
     if flake_check[2] != 0:
         logging.warning(
@@ -55,10 +71,17 @@ def get_derivations_from_check(nix_path: str, path_to_flake: str) -> list[str]:
 
 
 def get_derivations(path_to_flake: str) -> list[str]:
+    """Gets all derivations present in a flake.
+
+    :param path_to_flake: path to flake to be checked
+    :returns a list of all valid derivations in the flake
+    :raises RuntimeError: fails if nix is not present in the PATH
+    """
     nix_path = shutil.which("nix")
     derivations = []
     if nix_path is None:
-        raise RuntimeError("nix is not available in the PATH, please verify that it is installed")
+        status_msg = "nix is not available in the PATH, please verify that it is installed"
+        raise RuntimeError(status_msg)
     flake_show = bash_wrapper(f"{nix_path} flake show --json", path=path_to_flake)
     if flake_show[2] != 0:
         logging.error("flake show returned non-zero exit code")