implement C2401

crates/ruff_linter/resources/test/fixtures/pylint/non_ascii_name.py

@@ -0,0 +1,9 @@
+ápple_count: int = 1  # C2401
+ápple_count += 2  # C2401
+ápple_count = 3  # C2401
+
+# this rule only works on assignment!
+ápple_count == 3  # Ok
+
+# normal ascii
+apple_count = 4  # Ok

crates/ruff_linter/src/checkers/ast/analyze/statement.rs

@@ -1012,6 +1012,9 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             }
         }
         Stmt::AugAssign(ast::StmtAugAssign { target, .. }) => {
+            if checker.enabled(Rule::NonAsciiName) {
+                pylint::rules::non_ascii_name(checker, target);
+            }
             if checker.enabled(Rule::GlobalStatement) {
                 if let Expr::Name(ast::ExprName { id, .. }) = target.as_ref() {
                     pylint::rules::global_statement(checker, id);
@@ -1314,6 +1317,11 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             }
         }
         Stmt::Assign(assign @ ast::StmtAssign { targets, value, .. }) => {
+            if checker.enabled(Rule::NonAsciiName) {
+                for target in targets {
+                    pylint::rules::non_ascii_name(checker, target);
+                }
+            }
             if checker.enabled(Rule::LambdaAssignment) {
                 if let [target] = &targets[..] {
                     pycodestyle::rules::lambda_assignment(checker, target, value, None, stmt);
@@ -1427,6 +1435,9 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
                 ..
             },
         ) => {
+            if checker.enabled(Rule::NonAsciiName) {
+                pylint::rules::non_ascii_name(checker, target);
+            }
             if let Some(value) = value {
                 if checker.enabled(Rule::LambdaAssignment) {
                     pycodestyle::rules::lambda_assignment(

crates/ruff_linter/src/codes.rs

@@ -211,6 +211,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Pylint, "C0205") => (RuleGroup::Stable, rules::pylint::rules::SingleStringSlots),
         (Pylint, "C0208") => (RuleGroup::Stable, rules::pylint::rules::IterationOverSet),
         (Pylint, "C0414") => (RuleGroup::Stable, rules::pylint::rules::UselessImportAlias),
+        (Pylint, "C2401") => (RuleGroup::Preview, rules::pylint::rules::NonAsciiName),
         #[allow(deprecated)]
         (Pylint, "C1901") => (RuleGroup::Nursery, rules::pylint::rules::CompareToEmptyString),
         (Pylint, "C3002") => (RuleGroup::Stable, rules::pylint::rules::UnnecessaryDirectLambdaCall),

crates/ruff_linter/src/rules/pylint/mod.rs

@@ -139,6 +139,7 @@ mod tests {
     #[test_case(Rule::MisplacedBareRaise, Path::new("misplaced_bare_raise.py"))]
     #[test_case(Rule::LiteralMembership, Path::new("literal_membership.py"))]
     #[test_case(Rule::GlobalAtModuleLevel, Path::new("global_at_module_level.py"))]
+    #[test_case(Rule::NonAsciiName, Path::new("non_ascii_name.py"))]
     fn rules(rule_code: Rule, path: &Path) -> Result<()> {
         let snapshot = format!("{}_{}", rule_code.noqa_code(), path.to_string_lossy());
         let diagnostics = test_path(

crates/ruff_linter/src/rules/pylint/rules/mod.rs

@@ -34,6 +34,7 @@ pub(crate) use misplaced_bare_raise::*;
 pub(crate) use named_expr_without_context::*;
 pub(crate) use nested_min_max::*;
 pub(crate) use no_self_use::*;
+pub(crate) use non_ascii_name::*;
 pub(crate) use nonlocal_without_binding::*;
 pub(crate) use property_with_parameters::*;
 pub(crate) use redefined_loop_name::*;
@@ -99,6 +100,7 @@ mod misplaced_bare_raise;
 mod named_expr_without_context;
 mod nested_min_max;
 mod no_self_use;
+mod non_ascii_name;
 mod nonlocal_without_binding;
 mod property_with_parameters;
 mod redefined_loop_name;

crates/ruff_linter/src/rules/pylint/rules/non_ascii_name.rs

@@ -0,0 +1,41 @@
+use ruff_python_ast::{self as ast, Expr};
+
+use ruff_diagnostics::{Diagnostic, Violation};
+use ruff_macros::{derive_message_formats, violation};
+use ruff_text_size::Ranged;
+
+use crate::checkers::ast::Checker;
+
+/// ## What it does
+/// Checks for the use of non-ASCII characters in symbol names.
+///
+/// ## Why is this bad?
+/// Pylint discourages the use of non-ASCII characters in symbol names as
+/// they can cause confusion and compatibility issues.
+///
+/// ## References
+/// - [PEP 672](https://peps.python.org/pep-0672/)
+#[violation]
+pub struct NonAsciiName;
+
+impl Violation for NonAsciiName {
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        format!("Symbol name contains a non-ASCII character, consider renaming it.")
+    }
+}
+
+/// PLC2401
+pub(crate) fn non_ascii_name(checker: &mut Checker, target: &Expr) {
+    let Expr::Name(ast::ExprName { id, .. }) = target else {
+        return;
+    };
+
+    if id.is_ascii() {
+        return;
+    }
+
+    checker
+        .diagnostics
+        .push(Diagnostic::new(NonAsciiName, target.range()));
+}

crates/ruff_linter/src/rules/pylint/snapshots/ruff_linter__rules__pylint__tests__PLC2401_non_ascii_name.py.snap

@@ -0,0 +1,30 @@
+---
+source: crates/ruff_linter/src/rules/pylint/mod.rs
+---
+non_ascii_name.py:1:1: PLC2401 Symbol name contains a non-ASCII character, consider renaming it.
+  |
+1 | ápple_count: int = 1  # C2401
+  | ^^^^^^^^^^^ PLC2401
+2 | ápple_count += 2  # C2401
+3 | ápple_count = 3  # C2401
+  |
+
+non_ascii_name.py:2:1: PLC2401 Symbol name contains a non-ASCII character, consider renaming it.
+  |
+1 | ápple_count: int = 1  # C2401
+2 | ápple_count += 2  # C2401
+  | ^^^^^^^^^^^ PLC2401
+3 | ápple_count = 3  # C2401
+  |
+
+non_ascii_name.py:3:1: PLC2401 Symbol name contains a non-ASCII character, consider renaming it.
+  |
+1 | ápple_count: int = 1  # C2401
+2 | ápple_count += 2  # C2401
+3 | ápple_count = 3  # C2401
+  | ^^^^^^^^^^^ PLC2401
+4 | 
+5 | # this rule only works on assignment!
+  |
+
+