commit 43cfda9bfb005ac0f61debc5d36b69ea71fd50d8
Author: Mika <kontakt@donau2space.de>
Date:   Wed Mar 4 15:16:37 2026 +0000

    Add artifact.1/src/artifact_1/core.py

diff --git a/artifact.1/src/artifact_1/core.py b/artifact.1/src/artifact_1/core.py
new file mode 100644
index 0000000..fe9ec9c
--- /dev/null
+++ b/artifact.1/src/artifact_1/core.py
@@ -0,0 +1,100 @@
+from __future__ import annotations
+
+import statistics
+from dataclasses import dataclass
+from typing import List, Dict, Any
+import logging
+
+
+# Configure basic logging for CI readiness
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+
+class DataValidationError(Exception):
+    """Raised when input data does not conform to expected structure."""
+    pass
+
+
+@dataclass
+class TestResult:
+    group: str
+    pinned_status: str
+    warn_rate: float
+    unknown_rate: float
+    delta_t_rate: float
+
+    @staticmethod
+    def from_dict(d: Dict[str, Any]) -> 'TestResult':
+        required_fields = {'group', 'pinned_status', 'warn_rate', 'unknown_rate', 'delta_t_rate'}
+        if not isinstance(d, dict):
+            raise DataValidationError(f"Each entry must be a dict, got: {type(d)}")
+        missing = required_fields - d.keys()
+        if missing:
+            raise DataValidationError(f"Missing required fields: {missing}")
+        try:
+            return TestResult(
+                group=str(d['group']),
+                pinned_status=str(d['pinned_status']),
+                warn_rate=float(d['warn_rate']),
+                unknown_rate=float(d['unknown_rate']),
+                delta_t_rate=float(d['delta_t_rate'])
+            )
+        except (TypeError, ValueError) as e:
+            raise DataValidationError(f"Invalid field type: {e}") from e
+
+
+def analyze_ab_data(data: List[TestResult]) -> Dict[str, Any]:
+    """Analysiert A/B-Testdaten und berechnet aggregierte Kennzahlen pro Gruppe und Stratum.
+
+    Args:
+        data: Liste von TestResult-Objekten.
+
+    Returns:
+        Dictionary mit aggregierten Kennzahlen pro (group, pinned_status) Paarung.
+    """
+
+    if not isinstance(data, list):
+        raise DataValidationError("Input data must be a list of TestResult objects.")
+    
+    # Validate list contents
+    for idx, item in enumerate(data):
+        if not isinstance(item, TestResult):
+            raise DataValidationError(f"Item at index {idx} is not a TestResult instance.")
+
+    # Group data by (group, pinned_status)
+    grouped: Dict[tuple[str, str], Dict[str, list[float]]] = {}
+    for tr in data:
+        key = (tr.group, tr.pinned_status)
+        if key not in grouped:
+            grouped[key] = {
+                'warn_rate': [],
+                'unknown_rate': [],
+                'delta_t_rate': []
+            }
+        grouped[key]['warn_rate'].append(tr.warn_rate)
+        grouped[key]['unknown_rate'].append(tr.unknown_rate)
+        grouped[key]['delta_t_rate'].append(tr.delta_t_rate)
+
+    result: Dict[str, Any] = {}
+    for (group, pin_status), metrics in grouped.items():
+        try:
+            result.setdefault(group, {})[pin_status] = {
+                'mean_warn_rate': statistics.fmean(metrics['warn_rate']),
+                'mean_unknown_rate': statistics.fmean(metrics['unknown_rate']),
+                'mean_delta_t_rate': statistics.fmean(metrics['delta_t_rate']),
+                'count': len(metrics['warn_rate'])
+            }
+        except statistics.StatisticsError as e:
+            logger.error(f"Statistics computation failed for {group}, {pin_status}: {e}")
+            result.setdefault(group, {})[pin_status] = {
+                'mean_warn_rate': None,
+                'mean_unknown_rate': None,
+                'mean_delta_t_rate': None,
+                'count': 0
+            }
+
+    logger.info("Aggregated summary computed for %d group-pinned combinations.", len(result))
+    assert all(isinstance(v, dict) for v in result.values()), "Result must be a nested dictionary."
+
+    return result