Generate Giant observed products

layer_helpers.py

@@ -0,0 +1,54 @@
+import csv
+import hashlib
+from collections import Counter
+from pathlib import Path
+
+
+def read_csv_rows(path):
+    path = Path(path)
+    with path.open(newline="", encoding="utf-8") as handle:
+        return list(csv.DictReader(handle))
+
+
+def write_csv_rows(path, rows, fieldnames):
+    path = Path(path)
+    path.parent.mkdir(parents=True, exist_ok=True)
+    with path.open("w", newline="", encoding="utf-8") as handle:
+        writer = csv.DictWriter(handle, fieldnames=fieldnames)
+        writer.writeheader()
+        writer.writerows(rows)
+
+
+def stable_id(prefix, raw_key):
+    digest = hashlib.sha1(str(raw_key).encode("utf-8")).hexdigest()[:12]
+    return f"{prefix}_{digest}"
+
+
+def first_nonblank(rows, field):
+    for row in rows:
+        value = row.get(field, "")
+        if value:
+            return value
+    return ""
+
+
+def representative_value(rows, field):
+    values = [row.get(field, "") for row in rows if row.get(field, "")]
+    if not values:
+        return ""
+    counts = Counter(values)
+    return sorted(counts.items(), key=lambda item: (-item[1], item[0]))[0][0]
+
+
+def distinct_values(rows, field):
+    return sorted({row.get(field, "") for row in rows if row.get(field, "")})
+
+
+def compact_join(values, limit=3):
+    unique = []
+    seen = set()
+    for value in values:
+        if value and value not in seen:
+            seen.add(value)
+            unique.append(value)
+    return " | ".join(unique[:limit])