namedtuple: Expected string literal for tuple entry name

[laipz8200]

Environment data

• Language Server version: 2021.9.2
• OS and version: linux x64
• Python version (and distribution if applicable, e.g. Anaconda): 3.7.3 64-bit
• python.analysis.indexing: undefined
• python.analysis.typeCheckingMode: off

Expected behaviour

namedtuple should receive any Iterable[str] type data, but it prompts a problem.

The code runs correctly. In fact, it comes from this website. Is this a recommended practice?

Actual behaviour

Expected string literal for tuple entry name

Logs

Python Language Server Log

[Info  - 10:11:47 AM] Pylance language server 2021.9.2 (pyright eca6f1a5) starting
[Info  - 10:11:47 AM] Server root directory: /home/xxxxxx/.vscode/extensions/ms-python.vscode-pylance-2021.9.2/dist

Code Snippet / Additional information

def namedtuplefetchall(cursor):
    "Return all rows from a cursor as a namedtuple"
    desc = cursor.description
    nt_result = namedtuple('Result', [col[0] for col in desc])
    nt_result = namedtuple('Result', (col[0] for col in desc))
    return [nt_result(*row) for row in cursor.fetchall()]

[erictraut]

You're right, this should not generate an error. If you dynamically specify the entries of a namedtuple, the static type checker won't be able to reason about the names and types of the entries, but it's a legitimate use of namedtuple.

I've updated the code to eliminate the false positive error. It will be fixed in the next release.

[jakebailey]

This issue has been fixed in version 2021.9.3, which we've just released. You can find the changelog here: https://github.com/microsoft/pylance-release/blob/main/CHANGELOG.md#202193-22-september-2021