Nested attribute lookup for improved error messages executes property code

[Hiumee]

Bug report

Bug description:

The new error messages for nested attributes will execute descriptors/property code

Modified example from the change log. Gave the property a side effect (print)

from dataclasses import dataclass
from math import pi

@dataclass
class Circle:
 radius: float
 @property
 def area(self) -> float:
 print("Property 'area' accessed")
 return pi * self.radius**2

class Container:
 def __init__(self, inner: Circle) -> None:
 self.inner = inner

circle = Circle(radius=4.0)
container = Container(circle)
print(container.area)

Output

Property 'area' accessed
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 print(container.area)
 ^^^^^^^^^^^^^^
AttributeError: 'Container' object has no attribute 'area'. Did you mean '.inner.area' instead of '.area'?

Expected would be to not execute the code. This does not happen when the Container class has a property suggested

PR incoming

CPython versions tested on:

CPython main branch

Operating systems tested on:

Windows

Linked PRs

• gh-145413: Fix nested attribute suggestions executing property code #145414

[Hiumee]

fixed by #146188