DescribeLogGroups — Boto3 Docs 1.26.85 documentation

retentionInDays (integer) --

The number of days to retain the log events in the specified log group. Possible values are: 1, 3, 5, 7, 14, 30, 60, 90, 120, 150, 180, 365, 400, 545, 731, 1827, 2192, 2557, 2922, 3288, and 3653.

To set a log group so that its log events do not expire, use DeleteRetentionPolicy.