[server]: Add update_average_punctuality

server/src/functions/update_average_punctuality/lambda_function.py

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+import json
+import boto3
+import requests
+
+dynamodb = boto3.resource("dynamodb")
+table = dynamodb.Table("punctuality_by_objectID")
+API_URL = "https://281bc6mcm5.execute-api.us-east-1.amazonaws.com/transient_data?objectType=IrishRailTrain"
+
+def fetch_train_data():
+    response = requests.get(API_URL)
+    if response.status_code == 200:
+        return response.json()
+    else:
+        print(f"Failed to fetch data: {response.status_code}")
+        return []
+
+
+def update_punctuality(objectID, new_punctuality):
+    response = table.get_item(Key={"objectID": objectID})
+    if "Item" in response:
+        item = response["Item"]
+        old_avg = float(item["average_punctuality"])
+        count = int(item["count"])
+
+        # Calculate new average
+        new_avg = ((old_avg * count) + new_punctuality) / (count + 1)
+        count += 1
+
+        # Update the DynamoDB table
+        table.update_item(
+            Key={"objectID": objectID},
+            UpdateExpression="SET average_punctuality = :avg, count = :cnt",
+            ExpressionAttributeValues={":avg": new_avg, ":cnt": count}
+        )
+    else:
+        # Insert new train punctuality record
+        table.put_item(
+            Item={"objectID": objectID, "average_punctuality": new_punctuality, "count": 1}
+        )
+
+
+def lambda_handler(event, context):
+    train_data = fetch_train_data()
+    for train in train_data:
+        objectID = train.get("objectID")
+        punctuality = int(train.get("trainPunctuality", 0))
+
+        if objectID:
+            update_punctuality(objectID, punctuality)
+
+    return {
+        "statusCode": 200,
+        "body": json.dumps("Punctuality data updated successfully")
+    }

server/src/functions/update_average_punctuality/requirements.txt

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+boto3
+requests