# Python \`3.11\` frame structure and various changes

**URL:** <https://discuss.python.org/t/python-3-11-frame-structure-and-various-changes/17895>\
**Category:** Python Help\
**Created:** [August 2, 2022, 3:33pm UTC](https://discuss.python.org/t/python-3-11-frame-structure-and-various-changes/17895 "2022-08-02T15:33:44Z")\
**Posts on this page:** 1\
**Showing post:** 16

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**Author:** ![sumerc](https://sea2.discourse-cdn.com/flex002/user_avatar/discuss.python.org/sumerc/32/8364_2.png) [@sumerc](https://discuss.python.org/u/sumerc)\
**Post date:** [August 5, 2022, 8:15am UTC](https://discuss.python.org/t/python-3-11-frame-structure-and-various-changes/17895/16 "2022-08-05T08:15:10Z")

</div>

> \_PyFrame\_GetGenerator() takes a \_PyInterpreterFrame _, are you not getting a  
> compilation error passing a PyFrameObject_?

TBH, I have not tried using it yet. I just seen similar code in ceval.c and asked if this is the right way to do it. See [yappi/yappi/\_yappi.c at 0fd2b5f9b2885f7fd518e6a42c8ee4ab461c5f96 · sumerc/yappi · GitHub](https://github.com/sumerc/yappi/blob/0fd2b5f9b2885f7fd518e6a42c8ee4ab461c5f96/yappi/_yappi.c#L231). If you have any idea on how to do it, I would love to hear 🙂

> While this is all still fresh in your memory, would you mind briefly writing up  
> where you you need to delve into CPython internals. It would be really valuable.  
> We are trying to flesh out the API for the sort of introspection you are doing.

Sure. Would love to do that. I am writing what I need and WHY I need it for. That is because: maybe someone can suggest a better way(s) to do it.

1/  
`PyFrameObject->f_state`: I use this to differentiate a `await` and an exit. I need this distinction to measure wall-time of a specific coroutine. E.g., I did not increment function call count when function is yielded for an `await`. And currently, I am not sure on how to do it.

2/  
I use `frame->co_flags & CO_COROUTINE || frame->co_flags & CO_ITERABLE_COROUTINE || frame->co_flags & CO_ASYNC_GENERATOR` to determine if the running function is simply async or not.

3/  
`frame->co_varnames` The reason I need this is the same reason with the thread opened [here](https://discuss.python.org/t/getting-the-class-name-of-a-code-frame-object-in-cpython-3-11-c-api/17396) Get the class name if the function is a method. ` __qualname__ ` was not always possible before (2.7 times…), thus I did not change the implementation. There was also another issue on not using qualname (maybe performance), but I honestly do not remember…

4/  
`frame->f_code->co_flags & CO_VARARGS` and `max_arg_count = frame->f_code->co_argcount;` Capture arguments from the function arguments (by name or by positional index). We are using that in [Blackfire profiler](https://www.blackfire.io/python/) EXTENSIVELY. We have a metric system where we collect data whenever a specific function call happens:

e.g., collect the argument `query` whenever function name is equals to something:

`db.execute(query='select * ...')`.

If the function is built-in(C function) we read it from `frame->f_valuestack` and if the function is a normal Python function we use: `arg_name = PyTuple_GetItem(frame->f_code->co_varnames, int_arg_id-1);`

5/  
`(_pyctx_t *)PyThreadState_GET()->context;` I need this for async. profiling. Internally, every context is hold in another slot in a hash table where I aggregate measurements. From profiler’s perspective every context has a separate callstack so they need to be measured separately.

These are things I remember for now.

One question. if you don’t mind: Are you going to implement a new API to access these fields only or are you also going to restrict access to them as well?

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