AWS Lambda now supports Python 3.9 as both a managed runtime and a container base image. You can now author AWS Lambda functions in Python 3.9 and use its new features, such as support for TLS 1.3, new string and dictionary operations, and improved time zone support. Python 3.9 also includes performance optimizations that you can benefit from without making any code changes. For more information on Lambda’s support for Python 3.9, see our blog post at Python 3.9 runtime now available in AWS Lambda.
Source:: Amazon AWS