Disable recursive tracing of calls with sys.settrace

[AndyBarcia]

Similar to #56201 and #56201 (comment), the problem is that returning None in a tracer function disables tracing of the lines of a given frame, but the function calls are still recursively traced, and there doesn't seem to be a way of avoiding this.

My current use case is to trace some functions defined in my codebase, while avoiding recursively tracing functions defined outside. This is quite a problem for me, because the vast majority of function calls are for functions outside my codebase, so there is a very big and unnecessary overhead.

[gaogaotiantian]

This is the documented feature of sys.settrace and it's impossible to change that. We would break a lot of code out there. It's a guarantee that very function call will trigger sys.settrace, regardless of whether they are recursive. If you want something with better granularity, try sys.monitoring.