improve exception handling (#23722)

make pep8

lib/ansible/modules/cloud/amazon/ec2_vpc_subnet.py

@@ -126,6 +126,7 @@ def get_subnet_info(subnet):
 
     return subnet_info
 
+
 def subnet_exists(vpc_conn, subnet_id):
     filters = {'subnet-id': subnet_id}
     subnet = vpc_conn.get_all_subnets(filters=filters)
@@ -149,6 +150,8 @@ def create_subnet(vpc_conn, vpc_id, cidr, az, check_mode):
     except EC2ResponseError as e:
         if e.error_code == "DryRunOperation":
             subnet = None
+        elif e.error_code == "InvalidSubnet.Conflict":
+            raise AnsibleVPCSubnetCreationException("%s: the CIDR %s conflicts with another subnet with the VPC ID %s." % (e.error_code, cidr, vpc_id))
         else:
             raise AnsibleVPCSubnetCreationException(
                 'Unable to create subnet {0}, error: {1}'.format(cidr, e))

test/sanity/pep8/legacy-files.txt

@@ -181,7 +181,6 @@ lib/ansible/modules/cloud/amazon/ec2_vpc_nat_gateway.py
 lib/ansible/modules/cloud/amazon/ec2_vpc_net.py
 lib/ansible/modules/cloud/amazon/ec2_vpc_net_facts.py
 lib/ansible/modules/cloud/amazon/ec2_vpc_peer.py
-lib/ansible/modules/cloud/amazon/ec2_vpc_subnet.py
 lib/ansible/modules/cloud/amazon/ec2_vpc_vgw.py
 lib/ansible/modules/cloud/amazon/ec2_vpc_vgw_facts.py
 lib/ansible/modules/cloud/amazon/ec2_win_password.py