[pep8_naming] Avoid false positives on standard library functions with uppercase names (N802)

[w0nder1ng]

Summary

This change prevents the visit_* methods of ast.NodeVisitor/NodeTransformer and the do_* methods of http.server.BaseHTTPRequestHandler from triggering N802. See #9400 for more information.

In Lib/ast.py:

class NodeVisitor(object):
    def visit(self, node):
        """Visit a node."""
        method = 'visit_' + node.__class__.__name__
        visitor = getattr(self, method, self.generic_visit)
        return visitor(node)

Example usage

from ast import NodeVisitor

class Visitor(NodeVisitor):
    def visit_Constant(self, node):
        print(f"visited a constant with value {node.value}")

Previously, this would trigger a N802 violation, even though the uppercase name is the intended way of using those subclasses.

Test Plan

I added tests to pep8_naming/N802.py.

[github-actions]

ruff-ecosystem results

Linter (stable)

ℹ️ ecosystem check detected linter changes. (+3 -8 violations, +0 -0 fixes in 4 projects; 51 projects unchanged)

apache/airflow (+0 -6 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --no-preview --select ALL

- airflow-core/src/airflow/utils/scheduler_health.py:36:9: N802 Function name `do_GET` should be lowercase
- dev/breeze/src/airflow_breeze/commands/release_management_commands.py:3387:17: N802 Function name `visit_FunctionDef` should be lowercase
- scripts/ci/pre_commit/check_deferrable_default.py:45:9: N802 Function name `visit_FunctionDef` should be lowercase
- scripts/in_container/run_template_fields_check.py:52:9: N802 Function name `visit_FunctionDef` should be lowercase
- scripts/in_container/run_template_fields_check.py:57:9: N802 Function name `visit_Assign` should be lowercase
- scripts/in_container/run_template_fields_check.py:66:9: N802 Function name `visit_AnnAssign` should be lowercase

bokeh/bokeh (+0 -1 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --no-preview --select ALL

- tests/support/plugins/file_server.py:59:9: N802 Function name `do_GET` should be lowercase

langchain-ai/langchain (+2 -0 violations, +0 -0 fixes)

+ libs/cli/langchain_cli/namespaces/migrate/generate/utils.py:23:48: RUF100 [*] Unused `noqa` directive (unused: `N802`)
+ libs/cli/langchain_cli/namespaces/migrate/generate/utils.py:42:50: RUF100 [*] Unused `noqa` directive (unused: `N802`)

latchbio/latch (+1 -1 violations, +0 -0 fixes)

- src/latch_cli/auth/oauth2.py:89:17: N802 Function name `do_GET` should be lowercase
+ src/latch_cli/centromere/ast_parsing.py:32:58: RUF100 [*] Unused `noqa` directive (unused: `N802`)

Changes by rule (2 rules affected)

code	total	+ violation	- violation	+ fix	- fix
N802	8	0	8	0	0
RUF100	3	3	0	0	0

Linter (preview)

ℹ️ ecosystem check detected linter changes. (+3 -8 violations, +0 -0 fixes in 4 projects; 51 projects unchanged)

apache/airflow (+0 -6 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --preview --select ALL

- airflow-core/src/airflow/utils/scheduler_health.py:36:9: N802 Function name `do_GET` should be lowercase
- dev/breeze/src/airflow_breeze/commands/release_management_commands.py:3387:17: N802 Function name `visit_FunctionDef` should be lowercase
- scripts/ci/pre_commit/check_deferrable_default.py:45:9: N802 Function name `visit_FunctionDef` should be lowercase
- scripts/in_container/run_template_fields_check.py:52:9: N802 Function name `visit_FunctionDef` should be lowercase
- scripts/in_container/run_template_fields_check.py:57:9: N802 Function name `visit_Assign` should be lowercase
- scripts/in_container/run_template_fields_check.py:66:9: N802 Function name `visit_AnnAssign` should be lowercase

bokeh/bokeh (+0 -1 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --preview --select ALL

- tests/support/plugins/file_server.py:59:9: N802 Function name `do_GET` should be lowercase

langchain-ai/langchain (+2 -0 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --preview

+ libs/cli/langchain_cli/namespaces/migrate/generate/utils.py:23:48: RUF100 [*] Unused `noqa` directive (unused: `N802`)
+ libs/cli/langchain_cli/namespaces/migrate/generate/utils.py:42:50: RUF100 [*] Unused `noqa` directive (unused: `N802`)

latchbio/latch (+1 -1 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --preview

- src/latch_cli/auth/oauth2.py:89:17: N802 Function name `do_GET` should be lowercase
+ src/latch_cli/centromere/ast_parsing.py:32:58: RUF100 [*] Unused `noqa` directive (unused: `N802`)

Changes by rule (2 rules affected)

code	total	+ violation	- violation	+ fix	- fix
N802	8	0	8	0	0
RUF100	3	3	0	0	0

[MichaReiser]

I don't think the special handling for NodeVisitor is necessary because typeshed defines all methods on NodeVisitor and, therefore, using @typing.override works (mypy)

Special casing the http handler seems fine, while unfortunate

[w0nder1ng]

@typing.override was added in 3.12, so it's not available in 3.11 or earlier, which is where I ran into this issue. Could the NodeVisitor check be gated behind python version < 3.12?

[w0nder1ng]

@MichaReiser is this an acceptable solution?

[ntBre]

This looks reasonable to me if it's okay with @MichaReiser. I just had a few small suggestions.

Before 3.12 I think users could still get @override from typing_extensions, but I'm not sure if that would be a better approach.