nixos-rebuild-ng: remove tabulate as dependency

pkgs/by-name/ni/nixos-rebuild-ng/package.nix

@@ -35,10 +35,6 @@ python3Packages.buildPythonApplication rec {
     setuptools
   ];
 
-  dependencies = with python3Packages; [
-    tabulate
-  ];
-
   nativeBuildInputs = lib.optionals withShellFiles [
     installShellFiles
     python3Packages.shtab
@@ -94,9 +90,6 @@ python3Packages.buildPythonApplication rec {
           mypy
           pytest
           ruff
-          types-tabulate
-          # dependencies
-          tabulate
         ]
       );
     in

pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/__init__.py

@@ -12,7 +12,7 @@ from . import nix
 from .constants import EXECUTABLE, WITH_NIX_2_18, WITH_REEXEC, WITH_SHELL_FILES
 from .models import Action, BuildAttr, Flake, NRError, Profile
 from .process import Remote, cleanup_ssh
-from .utils import Args, LogFormatter
+from .utils import Args, LogFormatter, tabulate
 
 logger = logging.getLogger()
 logger.setLevel(logging.INFO)
@@ -448,8 +448,6 @@ def execute(argv: list[str]) -> None:
             if args.json:
                 print(json.dumps(generations, indent=2))
             else:
-                from tabulate import tabulate
-
                 headers = {
                     "generation": "Generation",
                     "date": "Build-date",
@@ -459,17 +457,7 @@ def execute(argv: list[str]) -> None:
                     "specialisations": "Specialisation",
                     "current": "Current",
                 }
-                # Not exactly the same format as legacy nixos-rebuild but close
-                # enough
-                table = tabulate(
-                    generations,
-                    headers=headers,
-                    tablefmt="plain",
-                    numalign="left",
-                    stralign="left",
-                    disable_numparse=True,
-                )
-                print(table)
+                print(tabulate(generations, headers=headers))
         case Action.REPL:
             if flake:
                 nix.repl_flake("toplevel", flake, **flake_build_flags)

pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/utils.py

@@ -1,5 +1,6 @@
 import logging
-from typing import TypeAlias, assert_never, override
+from collections.abc import Mapping, Sequence
+from typing import Any, TypeAlias, assert_never, override
 
 Args: TypeAlias = bool | str | list[str] | int | None
 
@@ -18,7 +19,7 @@ class LogFormatter(logging.Formatter):
         return formatter.format(record)
 
 
-def dict_to_flags(d: dict[str, Args]) -> list[str]:
+def dict_to_flags(d: Mapping[str, Args]) -> list[str]:
     flags = []
     for key, value in d.items():
         flag = f"--{'-'.join(key.split('_'))}"
@@ -44,3 +45,49 @@ def dict_to_flags(d: dict[str, Args]) -> list[str]:
             case _:
                 assert_never(value)
     return flags
+
+
+def remap_dicts(
+    dicts: Sequence[Mapping[str, Any]],
+    mappings: Mapping[str, str],
+) -> list[dict[str, Any]]:
+    return [{mappings.get(k, k): v for k, v in d.items()} for d in dicts]
+
+
+def tabulate(
+    data: Sequence[Mapping[str, Any]],
+    headers: Mapping[str, str] | None = None,
+) -> str:
+    """Convert a sequence of mappings in a tabular-style format for terminal.
+
+    It expects that all mappings (dicts) have the same keys as the first one,
+    otherwise it will misbehave.
+    """
+    if not data:
+        return ""
+
+    if headers:
+        data = remap_dicts(data, headers)
+
+    data_headers = list(data[0].keys())
+
+    column_widths = [
+        max(
+            len(str(header)),
+            *(len(str(row.get(header, ""))) for row in data),
+        )
+        for header in data_headers
+    ]
+
+    def format_row(row: Mapping[str, Any]) -> str:
+        s = (2 * " ").join(
+            f"{str(row[header]).ljust(width)}"
+            for header, width in zip(data_headers, column_widths)
+        )
+        return s.strip()
+
+    result = [format_row(dict(zip(data_headers, data_headers)))]
+    for row in data:
+        result.append(format_row(row))
+
+    return "\n".join(result)

pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_utils.py

@@ -1,3 +1,5 @@
+import textwrap
+
 import nixos_rebuild.utils as u
 
 
@@ -28,3 +30,22 @@ def test_dict_to_flags() -> None:
     ]
     r2 = u.dict_to_flags({"verbose": 0, "empty_list": []})
     assert r2 == []
+
+
+def test_remap_dicts() -> None:
+    assert u.remap_dicts(
+        [{"foo": 1, "bar": True}, {"qux": "keep"}],
+        {"foo": "Foo", "bar": "Bar"},
+    ) == [{"Foo": 1, "Bar": True}, {"qux": "keep"}]
+
+
+def test_tabulate() -> None:
+    assert u.tabulate([]) == ""
+    assert u.tabulate([{}]) == "\n"
+    assert u.tabulate(
+        [{"foo": 12345, "bar": ["abc", "cde"]}, {"foo": 345, "bar": 456}],
+        {"foo": "Foo", "bar": "Bar"},
+    ) == textwrap.dedent("""\
+        Foo    Bar
+        12345  ['abc', 'cde']
+        345    456""")