如何利用sys.callstats？

Question

我刚刚在 PyCharm 之后的 sys 模块中偶然发现了 callstats 自动完成建议它。否则我可能永远不会发现它因为它甚至没有在 docs

中被提及

help(sys.callstats) 给出这个：

 Help on built-in function callstats in module sys:
callstats(...)
    callstats() -> tuple of integers

    Return a tuple of function call statistics, if CALL_PROFILE was defined
    when Python was built.  Otherwise, return None.

    When enabled, this function returns detailed, implementation-specific
    details about the number of function calls executed. The return value is
    a 11-tuple where the entries in the tuple are counts of:
    0. all function calls
    1. calls to PyFunction_Type objects
    2. PyFunction calls that do not create an argument tuple
    3. PyFunction calls that do not create an argument tuple
       and bypass PyEval_EvalCodeEx()
    4. PyMethod calls
    5. PyMethod calls on bound methods
    6. PyType calls
    7. PyCFunction calls
    8. generator calls
    9. All other calls
    10. Number of stack pops performed by call_function()

现在我很好奇为什么它没有在任何地方被提及，以及是否有可能在 Python 的 Anaconda 构建中使用它。它 returns None 当我打电话给 sys.callstats() 所以我假设后者的答案是否定的。但是，我仍然有兴趣了解 Python 构建的实际输出结果这在哪里有效。

编辑：在接受答案下方的评论链接的 Issue28799 中，我们找到了 callstats 将被 Python 3.7 删除的原因。在实施即将推出的功能后，统计数据可能不会正确：

My problem is that with my work on FASTCALL, it became harder to track where the functions are called in practice. It maybe out of the Python/ceval.c file. I'm not sure that statistics are still computed correctly after my FASTCALL changes, and I don't know how to check it.

Python has already sys.setprofile(), cProfile and profile modules. There is also sys.settrace(). Do we still need CALL_PROFILE?

Attached patch removes the feature:

Calling the the untested and undocumented sys.callstats() function now emits a DeprecationWarning warning

Remove the PyEval_GetCallStats() function and its documentation

Answer 1

我对sys.callstats也很好奇，所以我用CALL_PROFILE标志编译了一个Python 2.7.12的二进制文件。使用零用户代码但只有 python bootstrap 个例程，sys.callstats() 的结果是：

PCALL_ALL 1691
PCALL_FUNCTION 371
PCALL_FAST_FUNCTION 363
PCALL_FASTER_FUNCTION 257
PCALL_METHOD 59
PCALL_BOUND_METHOD 58
PCALL_CFUNCTION 892
PCALL_TYPE 394
PCALL_GENERATOR 28
PCALL_OTHER 33
PCALL_POP 2005

Answer 2

不要。它未记录、未测试，并且 disabled in Python 3.7. If you want to do profiling, use cProfile, profile, or sys.setprofile.

目前，如果您从定义了 CALL_PROFILE 的源代码编译 Python 3.6 或 2.7，那么 sys.callstats 将完全按照文档字符串所说的那样使用 CALL_PROFILE 定义: 它 returns 一个包含各种内部调用类型计数的 11 元素元组。仅在 Python/ceval.c 中跟踪统计数据，因此它会错过未通过那里的呼叫。

如何利用sys.callstats？

How to utilize sys.callstats?

python

sys

python-3.x

anaconda