Simple script to update AWS Route 53 from a dynamic ip host

I run this in a cron job to update my home VPN server

route53me.py

@@ -0,0 +1,54 @@
+import boto3
+import requests
+import re
+import time
+
+# Replace below with correct hosted zone id, host name, and desired TTL
+hostedZoneId = 'ZK8XMWWB*****'
+hostName = 'host.dyn.example.com'
+ttl = 60
+
+# Any ip lookup service that returns just the ip address as text
+ipifyEndpoint = 'https://api.ipify.org'
+
+validIpRegex = '^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$'
+
+thisPublicIp = requests.get(ipifyEndpoint).text
+
+validIpPattern = re.compile(validIpRegex)
+
+validIpMatch = validIpPattern.match(thisPublicIp)
+
+if validIpMatch == None:
+  # Not a valid ip address
+  exit('Invalid IP Address: ' + thisPulbicIp)
+
+route53 = boto3.client('route53')
+
+route53.change_resource_record_sets(
+    HostedZoneId = hostedZoneId,
+    ChangeBatch = {
+        'Comment' : 'Last updated by route53me.py at ' % time.gmtime(),
+        'Changes' : [
+            {
+                'Action' : 'UPSERT',
+                'ResourceRecordSet' : 
+                {
+                    'Name' : hostName,
+                    'Type' : 'A',
+                    'TTL' : ttl,
+                    'ResourceRecords' :
+                    [
+                        {
+                            'Value' : thisPublicIp
+                        },
+                    ]
+                }
+            },
+        ]
+    }
+)
+
+print ('Updated to ' + thisPublicIp)
+
+