Remove CallArguments abstraction (#6279)

## Summary

This PR removes a now-unnecessary abstraction from `helper.rs`
(`CallArguments`), in favor of adding methods to `Arguments` directly,
which helps with discoverability.

crates/ruff/src/checkers/ast/analyze/expression.rs

@@ -528,19 +528,19 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
                 flake8_bandit::rules::exec_used(checker, func);
             }
             if checker.enabled(Rule::BadFilePermissions) {
-                flake8_bandit::rules::bad_file_permissions(checker, func, args, keywords);
+                flake8_bandit::rules::bad_file_permissions(checker, call);
             }
             if checker.enabled(Rule::RequestWithNoCertValidation) {
                 flake8_bandit::rules::request_with_no_cert_validation(checker, func, keywords);
             }
             if checker.enabled(Rule::UnsafeYAMLLoad) {
-                flake8_bandit::rules::unsafe_yaml_load(checker, func, args, keywords);
+                flake8_bandit::rules::unsafe_yaml_load(checker, call);
             }
             if checker.enabled(Rule::SnmpInsecureVersion) {
                 flake8_bandit::rules::snmp_insecure_version(checker, func, keywords);
             }
             if checker.enabled(Rule::SnmpWeakCryptography) {
-                flake8_bandit::rules::snmp_weak_cryptography(checker, func, args, keywords);
+                flake8_bandit::rules::snmp_weak_cryptography(checker, call);
             }
             if checker.enabled(Rule::Jinja2AutoescapeFalse) {
                 flake8_bandit::rules::jinja2_autoescape_false(checker, func, keywords);
@@ -552,9 +552,7 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
                 flake8_bandit::rules::hardcoded_sql_expression(checker, expr);
             }
             if checker.enabled(Rule::HashlibInsecureHashFunction) {
-                flake8_bandit::rules::hashlib_insecure_hash_functions(
-                    checker, func, args, keywords,
-                );
+                flake8_bandit::rules::hashlib_insecure_hash_functions(checker, call);
             }
             if checker.enabled(Rule::RequestWithoutTimeout) {
                 flake8_bandit::rules::request_without_timeout(checker, func, keywords);
@@ -765,9 +763,7 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
                 pylint::rules::nested_min_max(checker, expr, func, args, keywords);
             }
             if checker.enabled(Rule::PytestPatchWithLambda) {
-                if let Some(diagnostic) =
-                    flake8_pytest_style::rules::patch_with_lambda(func, args, keywords)
-                {
+                if let Some(diagnostic) = flake8_pytest_style::rules::patch_with_lambda(call) {
                     checker.diagnostics.push(diagnostic);
                 }
             }
@@ -788,7 +784,7 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
                 flake8_pytest_style::rules::raises_call(checker, func, args, keywords);
             }
             if checker.enabled(Rule::PytestFailWithoutMessage) {
-                flake8_pytest_style::rules::fail_call(checker, func, args, keywords);
+                flake8_pytest_style::rules::fail_call(checker, call);
             }
             if checker.enabled(Rule::PairwiseOverZipped) {
                 if checker.settings.target_version >= PythonVersion::Py310 {
@@ -874,10 +870,10 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
                 Rule::LoggingExcInfo,
                 Rule::LoggingRedundantExcInfo,
             ]) {
-                flake8_logging_format::rules::logging_call(checker, func, args, keywords);
+                flake8_logging_format::rules::logging_call(checker, call);
             }
             if checker.any_enabled(&[Rule::LoggingTooFewArgs, Rule::LoggingTooManyArgs]) {
-                pylint::rules::logging_call(checker, func, args, keywords);
+                pylint::rules::logging_call(checker, call);
             }
             if checker.enabled(Rule::DjangoLocalsInRenderFunction) {
                 flake8_django::rules::locals_in_render_function(checker, func, args, keywords);

crates/ruff/src/rules/flake8_bandit/rules/bad_file_permissions.rs

@@ -1,10 +1,9 @@
 use num_traits::ToPrimitive;
-use ruff_python_ast::{self as ast, Constant, Expr, Keyword, Operator, Ranged};
 
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
 use ruff_python_ast::call_path::CallPath;
-use ruff_python_ast::helpers::CallArguments;
+use ruff_python_ast::{self as ast, Constant, Expr, Operator, Ranged};
 use ruff_python_semantic::SemanticModel;
 
 use crate::checkers::ast::Checker;
@@ -48,19 +47,13 @@ impl Violation for BadFilePermissions {
 }
 
 /// S103
-pub(crate) fn bad_file_permissions(
-    checker: &mut Checker,
-    func: &Expr,
-    args: &[Expr],
-    keywords: &[Keyword],
-) {
+pub(crate) fn bad_file_permissions(checker: &mut Checker, call: &ast::ExprCall) {
     if checker
         .semantic()
-        .resolve_call_path(func)
+        .resolve_call_path(&call.func)
         .is_some_and(|call_path| matches!(call_path.as_slice(), ["os", "chmod"]))
     {
-        let call_args = CallArguments::new(args, keywords);
-        if let Some(mode_arg) = call_args.argument("mode", 1) {
+        if let Some(mode_arg) = call.arguments.find_argument("mode", 1) {
             if let Some(int_value) = int_value(mode_arg, checker.semantic()) {
                 if (int_value & WRITE_WORLD > 0) || (int_value & EXECUTE_GROUP > 0) {
                     checker.diagnostics.push(Diagnostic::new(

crates/ruff/src/rules/flake8_bandit/rules/hashlib_insecure_hash_functions.rs

@@ -1,8 +1,7 @@
-use ruff_python_ast::{Expr, Keyword, Ranged};
-
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_python_ast::helpers::{find_keyword, is_const_false, CallArguments};
+use ruff_python_ast::helpers::is_const_false;
+use ruff_python_ast::{self as ast, Arguments, Ranged};
 
 use crate::checkers::ast::Checker;
 
@@ -60,15 +59,11 @@ impl Violation for HashlibInsecureHashFunction {
 }
 
 /// S324
-pub(crate) fn hashlib_insecure_hash_functions(
-    checker: &mut Checker,
-    func: &Expr,
-    args: &[Expr],
-    keywords: &[Keyword],
-) {
-    if let Some(hashlib_call) = checker
+pub(crate) fn hashlib_insecure_hash_functions(checker: &mut Checker, call: &ast::ExprCall) {
+    if let Some(hashlib_call) =
+        checker
             .semantic()
-        .resolve_call_path(func)
+            .resolve_call_path(&call.func)
             .and_then(|call_path| match call_path.as_slice() {
                 ["hashlib", "new"] => Some(HashlibCall::New),
                 ["hashlib", "md4"] => Some(HashlibCall::WeakHash("md4")),
@@ -78,12 +73,12 @@ pub(crate) fn hashlib_insecure_hash_functions(
                 _ => None,
             })
     {
-        if !is_used_for_security(keywords) {
+        if !is_used_for_security(&call.arguments) {
             return;
         }
         match hashlib_call {
             HashlibCall::New => {
-                if let Some(name_arg) = CallArguments::new(args, keywords).argument("name", 0) {
+                if let Some(name_arg) = call.arguments.find_argument("name", 0) {
                     if let Some(hash_func_name) = string_literal(name_arg) {
                         // `hashlib.new` accepts both lowercase and uppercase names for hash
                         // functions.
@@ -106,15 +101,16 @@ pub(crate) fn hashlib_insecure_hash_functions(
                     HashlibInsecureHashFunction {
                         string: (*func_name).to_string(),
                     },
-                    func.range(),
+                    call.func.range(),
                 ));
             }
         }
     }
 }
 
-fn is_used_for_security(keywords: &[Keyword]) -> bool {
-    find_keyword(keywords, "usedforsecurity")
+fn is_used_for_security(arguments: &Arguments) -> bool {
+    arguments
+        .find_keyword("usedforsecurity")
         .map_or(true, |keyword| !is_const_false(&keyword.value))
 }
 

crates/ruff/src/rules/flake8_bandit/rules/snmp_weak_cryptography.rs

@@ -1,8 +1,6 @@
-use ruff_python_ast::{Expr, Keyword, Ranged};
-
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_python_ast::helpers::CallArguments;
+use ruff_python_ast::{self as ast, Ranged};
 
 use crate::checkers::ast::Checker;
 
@@ -42,21 +40,18 @@ impl Violation for SnmpWeakCryptography {
 }
 
 /// S509
-pub(crate) fn snmp_weak_cryptography(
-    checker: &mut Checker,
-    func: &Expr,
-    args: &[Expr],
-    keywords: &[Keyword],
-) {
+pub(crate) fn snmp_weak_cryptography(checker: &mut Checker, call: &ast::ExprCall) {
+    if call.arguments.len() < 3 {
         if checker
             .semantic()
-        .resolve_call_path(func)
-        .is_some_and(|call_path| matches!(call_path.as_slice(), ["pysnmp", "hlapi", "UsmUserData"]))
+            .resolve_call_path(&call.func)
+            .is_some_and(|call_path| {
+                matches!(call_path.as_slice(), ["pysnmp", "hlapi", "UsmUserData"])
+            })
         {
-        if CallArguments::new(args, keywords).len() < 3 {
             checker
                 .diagnostics
-                .push(Diagnostic::new(SnmpWeakCryptography, func.range()));
+                .push(Diagnostic::new(SnmpWeakCryptography, call.func.range()));
         }
     }
 }

crates/ruff/src/rules/flake8_bandit/rules/unsafe_yaml_load.rs

@@ -1,8 +1,6 @@
-use ruff_python_ast::{self as ast, Expr, Keyword, Ranged};
-
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_python_ast::helpers::CallArguments;
+use ruff_python_ast::{self as ast, Expr, Ranged};
 
 use crate::checkers::ast::Checker;
 
@@ -60,19 +58,13 @@ impl Violation for UnsafeYAMLLoad {
 }
 
 /// S506
-pub(crate) fn unsafe_yaml_load(
-    checker: &mut Checker,
-    func: &Expr,
-    args: &[Expr],
-    keywords: &[Keyword],
-) {
+pub(crate) fn unsafe_yaml_load(checker: &mut Checker, call: &ast::ExprCall) {
     if checker
         .semantic()
-        .resolve_call_path(func)
+        .resolve_call_path(&call.func)
         .is_some_and(|call_path| matches!(call_path.as_slice(), ["yaml", "load"]))
     {
-        let call_args = CallArguments::new(args, keywords);
-        if let Some(loader_arg) = call_args.argument("Loader", 1) {
+        if let Some(loader_arg) = call.arguments.find_argument("Loader", 1) {
             if !checker
                 .semantic()
                 .resolve_call_path(loader_arg)
@@ -93,7 +85,7 @@ pub(crate) fn unsafe_yaml_load(
         } else {
             checker.diagnostics.push(Diagnostic::new(
                 UnsafeYAMLLoad { loader: None },
-                func.range(),
+                call.func.range(),
             ));
         }
     }

crates/ruff/src/rules/flake8_logging_format/rules/logging_call.rs

@@ -1,7 +1,5 @@
-use ruff_python_ast::{self as ast, Arguments, Constant, Expr, Keyword, Operator, Ranged};
-
 use ruff_diagnostics::{Diagnostic, Edit, Fix};
-use ruff_python_ast::helpers::{find_keyword, CallArguments};
+use ruff_python_ast::{self as ast, Arguments, Constant, Expr, Keyword, Operator, Ranged};
 use ruff_python_semantic::analyze::logging;
 use ruff_python_stdlib::logging::LoggingLevel;
 
@@ -153,13 +151,8 @@ impl LoggingCallType {
 }
 
 /// Check logging calls for violations.
-pub(crate) fn logging_call(
-    checker: &mut Checker,
-    func: &Expr,
-    args: &[Expr],
-    keywords: &[Keyword],
-) {
-    let Expr::Attribute(ast::ExprAttribute { value: _, attr, .. }) = func else {
+pub(crate) fn logging_call(checker: &mut Checker, call: &ast::ExprCall) {
+    let Expr::Attribute(ast::ExprAttribute { value: _, attr, .. }) = call.func.as_ref() else {
         return;
     };
 
@@ -167,13 +160,17 @@ pub(crate) fn logging_call(
         return;
     };
 
-    if !logging::is_logger_candidate(func, checker.semantic(), &checker.settings.logger_objects) {
+    if !logging::is_logger_candidate(
+        &call.func,
+        checker.semantic(),
+        &checker.settings.logger_objects,
+    ) {
         return;
     }
 
     // G001 - G004
     let msg_pos = usize::from(matches!(logging_call_type, LoggingCallType::LogCall));
-    if let Some(format_arg) = CallArguments::new(args, keywords).argument("msg", msg_pos) {
+    if let Some(format_arg) = call.arguments.find_argument("msg", msg_pos) {
         check_msg(checker, format_arg);
     }
 
@@ -196,7 +193,7 @@ pub(crate) fn logging_call(
 
     // G101
     if checker.enabled(Rule::LoggingExtraAttrClash) {
-        if let Some(extra) = find_keyword(keywords, "extra") {
+        if let Some(extra) = call.arguments.find_keyword("extra") {
             check_log_record_attr_clash(checker, extra);
         }
     }
@@ -206,7 +203,7 @@ pub(crate) fn logging_call(
         if !checker.semantic().in_exception_handler() {
             return;
         }
-        let Some(exc_info) = logging::exc_info(keywords, checker.semantic()) else {
+        let Some(exc_info) = logging::exc_info(&call.arguments, checker.semantic()) else {
             return;
         };
         if let LoggingCallType::LevelCall(logging_level) = logging_call_type {

crates/ruff/src/rules/flake8_pytest_style/rules/fail.rs

@@ -1,8 +1,6 @@
-use ruff_python_ast::{Expr, Keyword, Ranged};
-
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_python_ast::helpers::CallArguments;
+use ruff_python_ast::{self as ast, Ranged};
 
 use crate::checkers::ast::Checker;
 
@@ -56,26 +54,25 @@ impl Violation for PytestFailWithoutMessage {
     }
 }
 
-pub(crate) fn fail_call(checker: &mut Checker, func: &Expr, args: &[Expr], keywords: &[Keyword]) {
-    if is_pytest_fail(func, checker.semantic()) {
-        let call_args = CallArguments::new(args, keywords);
-
+pub(crate) fn fail_call(checker: &mut Checker, call: &ast::ExprCall) {
+    if is_pytest_fail(&call.func, checker.semantic()) {
         // Allow either `pytest.fail(reason="...")` (introduced in pytest 7.0) or
         // `pytest.fail(msg="...")` (deprecated in pytest 7.0)
-        let msg = call_args
-            .argument("reason", 0)
-            .or_else(|| call_args.argument("msg", 0));
+        let msg = call
+            .arguments
+            .find_argument("reason", 0)
+            .or_else(|| call.arguments.find_argument("msg", 0));
 
         if let Some(msg) = msg {
             if is_empty_or_null_string(msg) {
                 checker
                     .diagnostics
-                    .push(Diagnostic::new(PytestFailWithoutMessage, func.range()));
+                    .push(Diagnostic::new(PytestFailWithoutMessage, call.func.range()));
             }
         } else {
             checker
                 .diagnostics
-                .push(Diagnostic::new(PytestFailWithoutMessage, func.range()));
+                .push(Diagnostic::new(PytestFailWithoutMessage, call.func.range()));
         }
     }
 }

crates/ruff/src/rules/flake8_pytest_style/rules/patch.rs

@@ -1,11 +1,10 @@
-use ruff_python_ast::{self as ast, Expr, Keyword, Parameters, Ranged};
-
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
 use ruff_python_ast::call_path::collect_call_path;
-use ruff_python_ast::helpers::{find_keyword, includes_arg_name, CallArguments};
+use ruff_python_ast::helpers::includes_arg_name;
 use ruff_python_ast::visitor;
 use ruff_python_ast::visitor::Visitor;
+use ruff_python_ast::{self as ast, Expr, Parameters, Ranged};
 
 #[violation]
 pub struct PytestPatchWithLambda;
@@ -44,13 +43,8 @@ where
     }
 }
 
-fn check_patch_call(
-    call: &Expr,
-    args: &[Expr],
-    keywords: &[Keyword],
-    new_arg_number: usize,
-) -> Option<Diagnostic> {
-    if find_keyword(keywords, "return_value").is_some() {
+fn check_patch_call(call: &ast::ExprCall, index: usize) -> Option<Diagnostic> {
+    if call.arguments.find_keyword("return_value").is_some() {
         return None;
     }
 
@@ -58,8 +52,9 @@ fn check_patch_call(
         parameters,
         body,
         range: _,
-    } = CallArguments::new(args, keywords)
-        .argument("new", new_arg_number)?
+    } = call
+        .arguments
+        .find_argument("new", index)?
         .as_lambda_expr()?;
 
     // Walk the lambda body.
@@ -72,16 +67,13 @@ fn check_patch_call(
     if visitor.uses_args {
         None
     } else {
-        Some(Diagnostic::new(PytestPatchWithLambda, call.range()))
+        Some(Diagnostic::new(PytestPatchWithLambda, call.func.range()))
     }
 }
 
-pub(crate) fn patch_with_lambda(
-    call: &Expr,
-    args: &[Expr],
-    keywords: &[Keyword],
-) -> Option<Diagnostic> {
-    let call_path = collect_call_path(call)?;
+/// PT008
+pub(crate) fn patch_with_lambda(call: &ast::ExprCall) -> Option<Diagnostic> {
+    let call_path = collect_call_path(&call.func)?;
 
     if matches!(
         call_path.as_slice(),
@@ -95,7 +87,7 @@ pub(crate) fn patch_with_lambda(
             "patch"
         ] | ["unittest", "mock", "patch"]
     ) {
-        check_patch_call(call, args, keywords, 1)
+        check_patch_call(call, 1)
     } else if matches!(
         call_path.as_slice(),
         [
@@ -109,7 +101,7 @@ pub(crate) fn patch_with_lambda(
             "object"
         ] | ["unittest", "mock", "patch", "object"]
     ) {
-        check_patch_call(call, args, keywords, 2)
+        check_patch_call(call, 2)
     } else {
         None
     }

crates/ruff/src/rules/pylint/rules/logging.rs

@@ -1,8 +1,6 @@
-use ruff_python_ast::{self as ast, Constant, Expr, Keyword, Ranged};
-
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_python_ast::helpers::CallArguments;
+use ruff_python_ast::{self as ast, Constant, Expr, Ranged};
 use ruff_python_semantic::analyze::logging;
 use ruff_python_stdlib::logging::LoggingLevel;
 
@@ -86,23 +84,23 @@ impl Violation for LoggingTooManyArgs {
 
 /// PLE1205
 /// PLE1206
-pub(crate) fn logging_call(
-    checker: &mut Checker,
-    func: &Expr,
-    args: &[Expr],
-    keywords: &[Keyword],
-) {
+pub(crate) fn logging_call(checker: &mut Checker, call: &ast::ExprCall) {
     // If there are any starred arguments, abort.
-    if args.iter().any(Expr::is_starred_expr) {
+    if call.arguments.args.iter().any(Expr::is_starred_expr) {
         return;
     }
 
     // If there are any starred keyword arguments, abort.
-    if keywords.iter().any(|keyword| keyword.arg.is_none()) {
+    if call
+        .arguments
+        .keywords
+        .iter()
+        .any(|keyword| keyword.arg.is_none())
+    {
         return;
     }
 
-    let Expr::Attribute(ast::ExprAttribute { attr, .. }) = func else {
+    let Expr::Attribute(ast::ExprAttribute { attr, .. }) = call.func.as_ref() else {
         return;
     };
 
@@ -110,16 +108,19 @@ pub(crate) fn logging_call(
         return;
     }
 
-    let call_args = CallArguments::new(args, keywords);
     let Some(Expr::Constant(ast::ExprConstant {
         value: Constant::Str(value),
         ..
-    })) = call_args.argument("msg", 0)
+    })) = call.arguments.find_argument("msg", 0)
     else {
         return;
     };
 
-    if !logging::is_logger_candidate(func, checker.semantic(), &checker.settings.logger_objects) {
+    if !logging::is_logger_candidate(
+        &call.func,
+        checker.semantic(),
+        &checker.settings.logger_objects,
+    ) {
         return;
     }
 
@@ -135,22 +136,22 @@ pub(crate) fn logging_call(
         return;
     }
 
-    let message_args = call_args.num_args() - 1;
+    let num_message_args = call.arguments.args.len() - 1;
+    let num_keywords = call.arguments.keywords.len();
 
     if checker.enabled(Rule::LoggingTooManyArgs) {
-        if summary.num_positional < message_args {
+        if summary.num_positional < num_message_args {
             checker
                 .diagnostics
-                .push(Diagnostic::new(LoggingTooManyArgs, func.range()));
+                .push(Diagnostic::new(LoggingTooManyArgs, call.func.range()));
         }
     }
 
     if checker.enabled(Rule::LoggingTooFewArgs) {
-        if message_args > 0 && call_args.num_kwargs() == 0 && summary.num_positional > message_args
-        {
+        if num_message_args > 0 && num_keywords == 0 && summary.num_positional > num_message_args {
             checker
                 .diagnostics
-                .push(Diagnostic::new(LoggingTooFewArgs, func.range()));
+                .push(Diagnostic::new(LoggingTooFewArgs, call.func.range()));
         }
     }
 }

crates/ruff/src/rules/tryceratops/rules/error_instead_of_exception.rs

@@ -66,7 +66,7 @@ pub(crate) fn error_instead_of_exception(checker: &mut Checker, handlers: &[Exce
         for expr in calls {
             if let Expr::Attribute(ast::ExprAttribute { attr, .. }) = expr.func.as_ref() {
                 if attr == "error" {
-                    if exc_info(&expr.arguments.keywords, checker.semantic()).is_none() {
+                    if exc_info(&expr.arguments, checker.semantic()).is_none() {
                         checker
                             .diagnostics
                             .push(Diagnostic::new(ErrorInsteadOfException, expr.range()));

crates/ruff_python_ast/src/helpers.rs

@@ -1034,64 +1034,6 @@ pub fn is_docstring_stmt(stmt: &Stmt) -> bool {
     }
 }
 
-/// A representation of a function call's positional and keyword arguments that ignores
-/// starred expressions.
-#[derive(Default)]
-pub struct CallArguments<'a> {
-    args: &'a [Expr],
-    keywords: &'a [Keyword],
-}
-
-impl<'a> CallArguments<'a> {
-    pub fn new(args: &'a [Expr], keywords: &'a [Keyword]) -> Self {
-        Self { args, keywords }
-    }
-
-    /// Get the argument with the given name or position, or `None` if no such
-    /// argument exists.
-    pub fn argument(&self, name: &str, position: usize) -> Option<&'a Expr> {
-        self.keywords
-            .iter()
-            .find(|keyword| {
-                let Keyword { arg, .. } = keyword;
-                arg.as_ref().is_some_and(|arg| arg == name)
-            })
-            .map(|keyword| &keyword.value)
-            .or_else(|| {
-                self.args
-                    .iter()
-                    .take_while(|expr| !expr.is_starred_expr())
-                    .nth(position)
-            })
-    }
-
-    /// Return the number of arguments.
-    pub fn len(&self) -> usize {
-        self.args.len() + self.keywords.len()
-    }
-
-    /// Return `true` if there are no arguments.
-    pub fn is_empty(&self) -> bool {
-        self.len() == 0
-    }
-
-    /// Return the number of positional arguments.
-    pub fn num_args(&self) -> usize {
-        self.args
-            .iter()
-            .take_while(|expr| !expr.is_starred_expr())
-            .count()
-    }
-
-    /// Return the number of keyword arguments.
-    pub fn num_kwargs(&self) -> usize {
-        self.keywords
-            .iter()
-            .filter(|keyword| keyword.arg.is_some())
-            .count()
-    }
-}
-
 /// Check if a node is part of a conditional branch.
 pub fn on_conditional_branch<'a>(parents: &mut impl Iterator<Item = &'a Stmt>) -> bool {
     parents.any(|parent| {

crates/ruff_python_ast/src/nodes.rs

@@ -2121,6 +2121,45 @@ pub struct Arguments {
     pub keywords: Vec<Keyword>,
 }
 
+impl Arguments {
+    /// Return the number of positional and keyword arguments.
+    pub fn len(&self) -> usize {
+        self.args.len() + self.keywords.len()
+    }
+
+    /// Return `true` if there are no positional or keyword arguments.
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    /// Return the [`Keyword`] with the given name, or `None` if no such [`Keyword`] exists.
+    pub fn find_keyword(&self, keyword_name: &str) -> Option<&Keyword> {
+        self.keywords.iter().find(|keyword| {
+            let Keyword { arg, .. } = keyword;
+            arg.as_ref().is_some_and(|arg| arg == keyword_name)
+        })
+    }
+
+    /// Return the argument with the given name or at the given position, or `None` if no such
+    /// argument exists. Used to retrieve arguments that can be provided _either_ as keyword or
+    /// positional arguments.
+    pub fn find_argument(&self, name: &str, position: usize) -> Option<&Expr> {
+        self.keywords
+            .iter()
+            .find(|keyword| {
+                let Keyword { arg, .. } = keyword;
+                arg.as_ref().is_some_and(|arg| arg == name)
+            })
+            .map(|keyword| &keyword.value)
+            .or_else(|| {
+                self.args
+                    .iter()
+                    .take_while(|expr| !expr.is_starred_expr())
+                    .nth(position)
+            })
+    }
+}
+
 /// An AST node used to represent a sequence of type parameters.
 ///
 /// For example, given:

crates/ruff_python_semantic/src/analyze/logging.rs

@@ -1,7 +1,6 @@
-use ruff_python_ast::{self as ast, Expr, Keyword};
-
 use ruff_python_ast::call_path::{collect_call_path, from_qualified_name};
-use ruff_python_ast::helpers::{find_keyword, is_const_true};
+use ruff_python_ast::helpers::is_const_true;
+use ruff_python_ast::{self as ast, Arguments, Expr, Keyword};
 
 use crate::model::SemanticModel;
 
@@ -61,8 +60,8 @@ pub fn is_logger_candidate(
 
 /// If the keywords to a  logging call contain `exc_info=True` or `exc_info=sys.exc_info()`,
 /// return the `Keyword` for `exc_info`.
-pub fn exc_info<'a>(keywords: &'a [Keyword], semantic: &SemanticModel) -> Option<&'a Keyword> {
-    let exc_info = find_keyword(keywords, "exc_info")?;
+pub fn exc_info<'a>(arguments: &'a Arguments, semantic: &SemanticModel) -> Option<&'a Keyword> {
+    let exc_info = arguments.find_keyword("exc_info")?;
 
     // Ex) `logging.error("...", exc_info=True)`
     if is_const_true(&exc_info.value) {