Getting "Cannot access member" error when inside a hasattr check

[kimadeline]

Environment data

• Language Server version: 2022.1.0 (pyright 5829dcbb)
• OS and version: macOS Big Sur 11.6.1
• Python version (& distribution if applicable, e.g. Anaconda): Python 3.8 venv

Expected behaviour

When using if hasattr to check if an attribute is present, I shouldn't get a "Cannot access member" error for code inside that condition.

Actual behaviour

I get the following error:

Cannot access member "decorator_list" for type "stmt"
  Member "decorator_list" is unknown (Pylance) reportGeneralTypeIssues

Logs

Copy-pasting the logs froze the window, so I am not going to include them. Let me know if you want them and I'll send them your way 🙂

Code Snippet / Additional information

import ast
import sys

tree = ast.parse("print('Hello World')")

for node in tree.body[1:]:
   line_end = node.lineno - 1
   if hasattr(node, "decorator_list") and sys.version_info.major >= 3:
      line_end -= len(node.decorator_list)

[bschnurr]

hasattr doesn't inform the correct type. If you want to use static typechecking look at isinstance

   if (isinstance(node, ast.FunctionDef) or isinstance(node, ast.AsyncFunctionDef) or isinstance(node, ast.ClassDef)) and sys.version_info.major >= 3:
      line_end -= len(node.decorator_list)

[kimadeline]

isinstance works, thanks! Sadly it can get a bit lengthy. If that's the only option available and having support for hasattr is not possible, feel free to close the issue.

[bschnurr]

could also try adding a typeguard function

microsoft/pyright#2852 (comment)