diff --git a/dmedvedev/python/15.functions.ipynb b/dmedvedev/python/15.functions.ipynb
index 34e0210..a7bb261 100644
--- a/dmedvedev/python/15.functions.ipynb
+++ b/dmedvedev/python/15.functions.ipynb
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 32,
    "id": "ad2441e7",
    "metadata": {},
    "outputs": [
@@ -156,7 +156,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 55,
    "id": "d3c6683e",
    "metadata": {},
    "outputs": [
@@ -172,11 +172,11 @@
    ],
    "source": [
     "def build_mart_name(entity_name, layer):\n",
-    "    print(f\"{layer}_{entity_name}\")\n",
+    "    return f\"{layer}_{entity_name}\"\n",
     "\n",
-    "build_mart_name(\"orders\", \"dm\")\n",
-    "build_mart_name(\"users\", \"core\")\n",
-    "build_mart_name(\"payments\", \"stg\")"
+    "print(build_mart_name(\"orders\", \"dm\"))\n",
+    "print(build_mart_name(\"users\", \"core\"))\n",
+    "print(build_mart_name(\"payments\", \"stg\"))"
    ]
   }
  ],
diff --git a/dmedvedev/python/16.varuables_on_default.ipynb b/dmedvedev/python/16.varuables_on_default.ipynb
index dd8f6c9..6a8c698 100644
--- a/dmedvedev/python/16.varuables_on_default.ipynb
+++ b/dmedvedev/python/16.varuables_on_default.ipynb
@@ -16,7 +16,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 59,
    "id": "2af8c0ea",
    "metadata": {},
    "outputs": [
@@ -30,9 +30,9 @@
    ],
    "source": [
     "def log_job_start(job_name, level = \"INFO\", env = \"dev\"):\n",
-    "    print(f\"[{level}] {job_name} load_users started in {env}\")\n",
+    "    print(f\"[{level}] Job {job_name} started in {env}\")\n",
     "\n",
-    "log_job_start(\"Job\")"
+    "log_job_start(\"load_users\")"
    ]
   },
   {
@@ -138,7 +138,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 94,
    "id": "ceb7c30b",
    "metadata": {},
    "outputs": [
@@ -148,7 +148,7 @@
        "'Row is valid'"
       ]
      },
-     "execution_count": 55,
+     "execution_count": 94,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -158,10 +158,11 @@
     "    if required_fields is None:\n",
     "        required_fields = [\"id\"]\n",
     "    for field in required_fields:\n",
-    "        if field not in required_fields:\n",
+    "        if field not in row:\n",
     "            return f\"Missing field: {field}\"\n",
-    "        else:\n",
-    "            return \"Row is valid\""
+    "    return \"Row is valid\"\n",
+    "\n",
+    "validate_row({\"id\": 1, \"email\":2}, [\"id\", \"email\"])"
    ]
   }
  ],