refector: optimized concurrent.futures

aws-subnets.py

@@ -16,15 +16,14 @@ def getRegions(all_regions=False):
     response = ec2.describe_regions(AllRegions=all_regions)
     return [region['RegionName'] for region in response['Regions']]
 
-def printResources(region_name: str) -> list[list[str | int]]:
+def getResources(region_name: str) -> list[list[str | int]]:
     return_data = []
     client = boto3.client('ec2', region_name=region_name)
     response = client.describe_subnets()
     for i in response['Subnets']:
         default_vpc_check = client.describe_vpcs(VpcIds=[i['VpcId']])
         for v in default_vpc_check['Vpcs']:
-            if i:
-                return_data.append([i['SubnetId'], i['VpcId'], i['CidrBlock'], i['AvailabilityZone'], v['IsDefault']])
+            return_data.append([i['SubnetId'], i['VpcId'], i['CidrBlock'], i['AvailabilityZone'], v['IsDefault']])
     return return_data
 
 # Main function
@@ -33,16 +32,14 @@ def main() -> None:
     wb = load_workbook('aws-inventory.xlsx')
     ws = wb.create_sheet("Subnets")
 
-    final_data = []
     ws.append(["SubnetId", "VpcId", "CidrBlock", "AvailabilityZone", "InDefaultVpc"])
-    with concurrent.futures.ProcessPoolExecutor(max_workers=6) as executor:
-        futures = [executor.submit(printResources, region_name=r) for r in getRegions()]
-        for future in concurrent.futures.as_completed(futures):
-            region_data = future.result()
-            final_data.extend(region_data)
-
-    for row in final_data:
-        ws.append(row)
+    with concurrent.futures.ThreadPoolExecutor(max_workers=8) as executor:
+        results = executor.map(getResources, getRegions())
+        for region_rows in results:
+            # append to worksheet only if resoruces are found in the region
+            if region_rows:
+                for row in region_rows:
+                    ws.append(row)
 
     wb.save('aws-inventory.xlsx')