diff --git a/docs/howto/filtering_deep_dive.ipynb b/docs/howto/filtering_deep_dive.ipynb
index 389d55b1..1a7826b2 100644
--- a/docs/howto/filtering_deep_dive.ipynb
+++ b/docs/howto/filtering_deep_dive.ipynb
@@ -2056,7 +2056,7 @@
     "    :return bool: True if it matches, False if it doesn't match\n",
     "    \"\"\"\n",
     "    # Perform regex match on host name and return boolean\n",
-    "    if re.match(\".+\\-[0-9][2,4,6,8,0].+\", host.name):\n",
+    "    if re.match(r\".*-\\d[24680].*\", host.name):\n",
     "        return True\n",
     "    else:\n",
     "        return False\n",
@@ -2074,7 +2074,7 @@
     "    :return bool: True if it matches, False if it doesn't match\n",
     "    \"\"\"\n",
     "    # Perform regex match on host name and return boolean\n",
-    "    if re.match(\"\\w{3}\\-\\w+\\-\\d{2}.\\w{3}.norn.local\", host.name):\n",
+    "    if re.match(r\"\\w{3}-\\w+-\\d{2}\\.\\w{3}\\.norn\\.local\", host.name):\n",
     "        return True\n",
     "    else:\n",
     "        return False\n",
@@ -2092,7 +2092,7 @@
     "    :return bool: True if does not match, False if it matches the convention\n",
     "    \"\"\"\n",
     "    # Perform regex match on host name and return boolean\n",
-    "    if re.match(\"\\w{3}\\-\\w+\\-\\d{2}.\\w{3}.norn.local\", host.name):\n",
+    "    if re.match(r\"\\w{3}-\\w+-\\d{2}\\.\\w{3}\\.norn\\.local\", host.name):\n",
     "        return False\n",
     "    else:\n",
     "        return True\n",