How to determine the position of a method in a call chain?

Question

Python

Greetings!
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I need an object for call tracing.

class MyTracerClass:
    def __init__(self):
        self._trace = []

    def __getattr__(self, item):
        # как вот здесь определить, что дальше ничего не вызывается?
        self._trace.append(item)
        return self


tracer = MyTracerClass()
tracer.aaa.bbb.xxx

How to understand from inside the tracer object that after the methods / parameters aaa, bbb something was called, but xxx was the last one in the chain? Not calling any more additional methods after xxx .
The names of methods / parameters and their number can be different, it is important for me to understand how to determine the last method / parameter in a line.
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PS: Maybe you can see from the object the line of code in which this object is accessed?
Thanks:)