Update app/app.py

app/app.py

@@ -15,6 +15,27 @@ from utils.evaluation import evaluate_response
 from utils.guardrails import validate_input, validate_output
 
 
+# --- NLTK bootstrap (fixes LookupError: punkt_tab) ---
+import os, nltk, pathlib
+
+NLTK_DATA_DIR = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "nltk_data"))
+os.makedirs(NLTK_DATA_DIR, exist_ok=True)
+os.environ.setdefault("NLTK_DATA", NLTK_DATA_DIR)
+
+def _ensure_nltk_data():
+    for res in ("punkt_tab", "punkt"):  # try new, then old
+        try:
+            nltk.data.find(f"tokenizers/{res}")
+        except LookupError:
+            try:
+                nltk.download(res, download_dir=NLTK_DATA_DIR, quiet=True, raise_on_error=True)
+            except Exception:
+                pass
+
+_ensure_nltk_data()
+# --- end NLTK bootstrap ---
+
+
 # ---------------------------
 # Streamlit Page Config
 # ---------------------------