Write file name based on return - python-3.x

Question

I'm creating a boto3 script that scrapes and uploads our entire accounts Public Ips and NatGateway Ips to our S3 bucket. I'm stuck on writing files for both returns. I would ideally like to write two separate files while still using the same filename variable you see in main(). Right now I can get this to work with only one return(either nat_ips or public_ips)
import boto3
from datetime import datetime
from csv import writer
def get_ips():
# Uses STS to assume the role needed.
boto_sts=boto3.client('sts')
sts_response = boto_sts.assume_role(
RoleArn='arn:aws:iam::1234:role/foo',
RoleSessionName='Foo'
)
# Save the details from assumed role into vars
sts_credentials = sts_response["Credentials"]
session_id = sts_credentials["AccessKeyId"]
session_key = sts_credentials["SecretAccessKey"]
session_token = sts_credentials["SessionToken"]
# List and store all the regions
ec2_client=boto3.client('ec2',aws_access_key_id=session_id,aws_secret_access_key=session_key,aws_session_token=session_token,region_name='us-west-1')
all_regions=[region['RegionName'] for region in ec2_client.describe_regions()['Regions']]
nat_ips = []
public_ips = []
for region in all_regions:
max_results = 1000
next_token = ''
ec2_client=boto3.client('ec2',aws_access_key_id=session_id,aws_secret_access_key=session_key,aws_session_token=session_token,region_name=region)
session=boto3.Session(aws_access_key_id=session_id, aws_secret_access_key=session_key, aws_session_token=session_token, region_name=region)
while next_token or next_token == '':
response = ec2_client.describe_nat_gateways(MaxResults=max_results, NextToken=next_token)
filters = [{'Name':'tag:Name', 'Values':['*sgw-eip']}]
get_ips = ec2_client.describe_addresses(Filters=filters)
for gateway in response["NatGateways"]:
for address in gateway["NatGatewayAddresses"]:
nat_ips.append(address["PublicIp"]+'/32')
for eip_dict in get_ips['Addresses']:
public_ip_string = eip_dict['Tags'][0]['Value'] + ' : ' + eip_dict['PublicIp']
public_ips.append(public_ip_string)
next_token = response.get("NextToken", None)
return nat_ips, public_ips
def _s3_upload(filename):
s3 = boto3.resource('s3')
bucket = 'foo-bar'
object_name = 'foo/'
s3.meta.client.upload_file(Filename=filename,Bucket=bucket,Key=object_name+filename)
print(f'Uploading {filename} to {bucket}')
def write_list_to_file(filename, data):
lines_string = '\n'.join(str(x) for x in data)
with open(filename,'w') as output:
output.writelines(lines_string)
print(f'Writing file to {filename}')
if __name__ == "__main__":
date = datetime.now().strftime('%Y%m%d')
# Stuck here since I want to make it one variable
filename_nat_ips = f'natgateway_ips{date}.csv'
filename_sga_ips = f'sga_ips{date}.csv'
public_ips = get_ips()
nat_ips = get_ips()
print(filename)
write_list_to_file(filename, nat_ips)
_s3_upload(filename)

Answer 1

I see that you are already returning a tuple of public_ips and nat_ips from your get_ips() function. So in your main, you could collect them together as well.
You might try something like this:
if __name__ == "__main__":
date = datetime.now().strftime('%Y%m%d')
# Stuck here since I want to make it one variable
filename_nat_ips = f'natgateway_ips{date}.csv'
filename_sga_ips = f'sga_ips{date}.csv'
nat_ips, public_ips = get_ips()
write_list_to_file(filename_nat_ips, nat_ips)
write_list_to_file(filename_public_ips, public_ips)
_s3_upload(filename_nat_ips)
_s3_upload(filename_public_ips)

Answer 2

I was doing it right the first time. And was trying to make it more complicated.
if __name__ == "__main__":
date = datetime.now().strftime('%Y%m%d')
filename_nat_ips = f'natgateway_ips{date}.csv'
filename_sga_ips = f'sga_ips{date}.csv'
nat_ips, public_ips = get_ips()
print(filename_nat_ips)
print(filename_sga_ips)
write_list_to_file(filename_nat_ips, nat_ips)
write_list_to_file(filename_sga_ips, public_ips)
_s3_upload(filename_nat_ips)
_s3_upload(filename_sga_ips)