这个 AttributeError 消息在 CPython 中在哪里实现？

Question

我认为 Python 会话中的 AttributeError 消息

>>> class A: pass
... 
>>> A().x
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'A' object has no attribute 'x'

在函数_PyObject_GenericGetAttrWithDict at these lines in CPython:

中实现

    if (!suppress) {
        PyErr_Format(PyExc_AttributeError,
                     "'%.50s' object has no attribute '%U'",
                     tp->tp_name, name);
    }

但是我找不到 AttributeError 消息在此 Python 会话中的位置

>>> class A: __slots__ = ('x',)
... 
>>> A().x
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: x

在CPython中实现。您能否为 GitHub 存储库中的确切行提供 link？

Answer 1

是here:

case T_OBJECT_EX:
    v = *(PyObject **)addr;
    if (v == NULL)
        PyErr_SetString(PyExc_AttributeError, l->name);
    Py_XINCREF(v);
    break;

这是 PyMember_GetOne 的摘录，其中实现了插槽描述符的 __get__ 方法的大部分逻辑。

您可能还对该描述符如何到达那里感兴趣。 type.__new__ 内部 translates __slots__ to an array of PyMemberDef structs, one of the mechanisms classes written in C use to define access to their internal data. All PyMemberDef structs generated this way are marked T_OBJECT_EX, meaning they correspond to a PyObject * in the instance memory layout, and if the pointer is null, access should raise an AttributeError. PyType_Ready then generates 基于 PyMemberDef 数组的插槽描述符。

这个 AttributeError 消息在 CPython 中在哪里实现？

Where is this AttributeError message implemented in CPython?

python

attributeerror

cpython

python-internals