Getting _csv.Error: iterator should return strings with Python3

[snehadesoftech]

(custodian) root@ip-172-31-29-218:/home/raxak/aws-security-benchmark/aws_cis_foundation_framework# python -V
Python 3.6.8
(custodian) root@ip-172-31-29-218:/home/raxak/aws-security-benchmark/aws_cis_foundation_framework# python aws-cis-foundation-benchmark-checklist.py
Traceback (most recent call last):
File "aws-cis-foundation-benchmark-checklist.py", line 2403, in
lambda_handler("test", "test")
File "aws-cis-foundation-benchmark-checklist.py", line 2260, in lambda_handler
cred_report = get_cred_report()
File "aws-cis-foundation-benchmark-checklist.py", line 1947, in get_cred_report
for row in reader:
File "/usr/lib/python3.6/csv.py", line 112, in next
row = next(self.reader)
_csv.Error: iterator should return strings, not bytes (did you open the file in text mode?)