Improve benchmark runner error handling and Python compatibility

- Add error handling for malformed JSON in benchmark output parsing
- Fix division-by-zero edge case in ratio calculation
- Use string-quoted type hints in Python for broader compatibility

Agent-Logs-Url: https://github.com/githubnext/tsessebe/sessions/4b3aa7c2-4060-4c79-b63c-1717b2502bb1

Co-authored-by: mrjf <180956+mrjf@users.noreply.github.com>

Author: Copilot

benchmarks/pandas/bench_series_creation.py

@@ -15,7 +15,7 @@
 ITERATIONS = 50
 
 
-def generate_data(n: int) -> list[float]:
+def generate_data(n: int) -> "list[float]":
     """Generate a deterministic numeric array of the given size."""
     return [i * 1.1 + 0.5 for i in range(n)]
 
@@ -27,7 +27,7 @@ def generate_data(n: int) -> list[float]:
     pd.Series(list(data))
 
 # Measured runs
-times: list[float] = []
+times: "list[float]" = []
 for _ in range(ITERATIONS):
     start = time.perf_counter()
     pd.Series(list(data))

benchmarks/results.json

@@ -1,4 +1 @@
-{
-  "benchmarks": [],
-  "timestamp": null
-}
+{"benchmarks": [], "timestamp": null}

benchmarks/run_benchmarks.sh

@@ -65,11 +65,27 @@ for ts_bench in "$SCRIPT_DIR"/tsb/bench_*.ts; do
   echo "  pandas result: $py_result"
 
   # Extract mean_ms from both
-  ts_mean=$(echo "$ts_result" | python3 -c "import sys, json; print(json.load(sys.stdin)['mean_ms'])")
-  py_mean=$(echo "$py_result" | python3 -c "import sys, json; print(json.load(sys.stdin)['mean_ms'])")
+  ts_mean=$(echo "$ts_result" | python3 -c "import sys, json; d=json.load(sys.stdin); print(d['mean_ms'])" 2>/dev/null) || {
+    echo "  ERROR: could not parse tsb benchmark result"
+    continue
+  }
+  py_mean=$(echo "$py_result" | python3 -c "import sys, json; d=json.load(sys.stdin); print(d['mean_ms'])" 2>/dev/null) || {
+    echo "  ERROR: could not parse pandas benchmark result"
+    continue
+  }
 
   # Calculate ratio (tsb / pandas) — < 1.0 means tsb is faster
-  ratio=$(python3 -c "print(round($ts_mean / $py_mean if $py_mean > 0 else 0, 3))")
+  ratio=$(python3 -c "
+ts, py = $ts_mean, $py_mean
+if py <= 0:
+    print('null')
+else:
+    print(round(ts / py, 3))
+")
+  if [ "$ratio" = "null" ]; then
+    echo "  ERROR: pandas mean_ms is zero, cannot compute ratio"
+    continue
+  fi
 
   echo "  Ratio (tsb/pandas): ${ratio}x"
   echo ""