No, I do not believe it is possible to monitor Python Lambda functions at this time. Currently looks like Dynatrace supports Node.js Lambda functions.
Unfortunately I am not able to comment on the roadmap of when it will be available. I will leave that to someone else.
I think the best approach here would be to contact product managers - @Sonja C. or @Daniel K. For FaaS in general, Dynatrace is moving towards OpenTelemetry, since there are technical limits in running OneAgent in FaaS environments and it even does not make much sense running a full or PaaS agent version there.See @Christoph_Neum answer for up 2 date solution (May 2021).
In January 2021, we released distributed tracing support for Python (and Java, Node.js) with full auto-instrumentation capabilities and deployment via Lambda Layers.