chore: fix ruff lint warnings and signal handling edge cases

- Fix pre-existing ruff lint warnings (F401, F541, F841, E741)
- Exclude .md/.json/.yml from ruff format check
- Unblock SIGTERM/SIGINT via pthread_sigmask in early signal handler
- Do not restore SIG_DFL on unregister to prevent pending signal kills

astrai/parallel/signal_handler.py

@@ -24,6 +24,17 @@ def _early_handler(signum: int, frame):
 def install_early_signal_handlers():
     for sig in (signal.SIGTERM, signal.SIGINT):
         signal.signal(sig, _early_handler)
+    _unblock_signals()
+
+
+def _unblock_signals():
+    try:
+        mask = signal.pthread_sigmask(signal.SIG_BLOCK, set())
+        blocked = {signal.SIGTERM, signal.SIGINT} & mask
+        if blocked:
+            signal.pthread_sigmask(signal.SIG_UNBLOCK, blocked)
+    except (AttributeError, OSError):
+        pass
 
 
 def register_signal_handlers(context):
@@ -40,5 +51,3 @@ def unregister_signal_handlers():
     global _active_context
     _active_context = None
     _early_stop.clear()
-    signal.signal(signal.SIGTERM, signal.SIG_DFL)
-    signal.signal(signal.SIGINT, signal.SIG_DFL)

astrai/trainer/strategy.py

@@ -1,7 +1,7 @@
 """Training strategy implementations with factory pattern."""
 
 from abc import ABC, abstractmethod
-from typing import Callable, Dict, Optional, Union
+from typing import Callable, Dict, Union
 
 import torch
 import torch.nn as nn

pyproject.toml

@@ -50,3 +50,4 @@ quote-style = "double"
 indent-style = "space"
 skip-magic-trailing-comma = false
 line-ending = "auto"
+exclude = ["*.md", "*.json", "*.yml", "*.yaml"]

scripts/eval/analyze_weights.py

@@ -143,7 +143,7 @@ def print_layer_grid(results: dict[str, dict]):
     widths = [6] + [10] * len(comps)
     metric = "er_99_norm"
 
-    print(f"\n--- Per-Layer Effective Rank (99% energy) ---")
+    print("\n--- Per-Layer Effective Rank (99% energy) ---")
     print(format_header(["Layer"] + comps, widths))
     print("-" * sum(widths))
 
@@ -173,7 +173,7 @@ def print_layer_grid(results: dict[str, dict]):
 def print_weight_stats(results: dict[str, dict]):
     groups = group_by_component(results)
     widths = [20, 12, 12, 12, 12]
-    print(f"\n--- Weight Value Statistics ---")
+    print("\n--- Weight Value Statistics ---")
     print(format_header(["Component", "Mean", "Std", "Min", "Max"], widths))
     print("-" * sum(widths))
 
@@ -265,7 +265,7 @@ def main():
             )
         print(f"{'=' * 70}")
 
-        print(f"Loading weights...")
+        print("Loading weights...")
         sd = safetensors.torch.load_file(str(weights_path))
         print(f"  {len(sd)} keys loaded")
 

scripts/eval/evaluate_mmlu.py

@@ -215,7 +215,6 @@ def _permute_choices(item: dict, rng: random.Random) -> tuple[dict, str]:
     positional bias (e.g. always picking B).
     """
     letters = ("A", "B", "C", "D")
-    contents = [item[k] for k in letters]
     perm = list(letters)
     rng.shuffle(perm)
     permuted = {"question": item["question"]}

scripts/eval/evaluate_ppl.py

@@ -148,7 +148,7 @@ class LossAccumulator:
         self.total += sum(losses)
         self.count += len(losses)
         if self.stream:
-            clamped = [min(max(l, 0.0), self._HIST_MAX) for l in losses]
+            clamped = [min(max(v, 0.0), self._HIST_MAX) for v in losses]
             idx = torch.tensor(clamped) / self._HIST_MAX * (self._HIST_BINS - 1)
             self.hist += torch.bincount(
                 idx.long().clamp(0, self._HIST_BINS - 1),
@@ -315,7 +315,7 @@ def print_stats(label: str, stats: Dict):
             )
     by_type = stats.get("by_token_type", {})
     if by_type:
-        print(f"\n  by token type:")
+        print("\n  by token type:")
         print(f"  {'type':<12} {'count':>8} {'mean_loss':>10} {'ppl':>8}")
         print(f"  {'-' * 12} {'-' * 8} {'-' * 10} {'-' * 8}")
         for ttype, s in by_type.items():

tests/data/test_dataset.py

@@ -824,7 +824,7 @@ def test_grpo_builder_preserves_response_boundaries(base_test_env):
     from tests.data.conftest import make_grpo_no_template_config
 
     tokenizer = base_test_env["tokenizer"]
-    tokenizer_path = _save_test_tokenizer(base_test_env["test_dir"], tokenizer)
+    _save_test_tokenizer(base_test_env["test_dir"], tokenizer)
 
     builder = SectionedMaskBuilder()
     config = make_grpo_no_template_config()