Respect start index in unnecessary-list-index-lookup

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

@@ -62,3 +62,17 @@ def value_intentionally_unused():
         print(letters[index])  # OK
         blah = letters[index]  # OK
         letters[index] = "d"  # OK
+
+
+def start():
+    # OK
+    for index, list_item in enumerate(some_list, start=1):
+        print(some_list[index])
+
+    # PLR1736
+    for index, list_item in enumerate(some_list, start=0):
+        print(some_list[index])
+
+    # PLR1736
+    for index, list_item in enumerate(some_list):
+        print(some_list[index])

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

@@ -1,7 +1,7 @@
 use ruff_diagnostics::{AlwaysFixableViolation, Diagnostic, Edit, Fix};
 use ruff_macros::{derive_message_formats, violation};
 use ruff_python_ast::visitor::Visitor;
-use ruff_python_ast::{self as ast, Expr, StmtFor};
+use ruff_python_ast::{self as ast, Expr, Int, Number, StmtFor};
 use ruff_python_semantic::SemanticModel;
 use ruff_text_size::Ranged;
 
@@ -151,6 +151,19 @@ fn enumerate_items<'a>(
         return None;
     };
 
+    // If the `enumerate` call has a non-zero `start`, don't omit.
+    if !arguments.find_argument("start", 1).map_or(true, |expr| {
+        matches!(
+            expr,
+            Expr::NumberLiteral(ast::ExprNumberLiteral {
+                value: Number::Int(Int::ZERO),
+                ..
+            })
+        )
+    }) {
+        return None;
+    }
+
     // Check that the function is the `enumerate` builtin.
     if !semantic.match_builtin_expr(func, "enumerate") {
         return None;

crates/ruff_linter/src/rules/pylint/snapshots/ruff_linter__rules__pylint__tests__PLR1736_unnecessary_list_index_lookup.py.snap

@@ -181,3 +181,40 @@ unnecessary_list_index_lookup.py:19:16: PLR1736 [*] List index lookup in `enumer
 20 20 | 
 21 21 | 
 22 22 | def dont_fix_these():
+
+unnecessary_list_index_lookup.py:74:15: PLR1736 [*] List index lookup in `enumerate()` loop
+   |
+72 |     # PLR1736
+73 |     for index, list_item in enumerate(some_list, start=0):
+74 |         print(some_list[index])
+   |               ^^^^^^^^^^^^^^^^ PLR1736
+75 | 
+76 |     # PLR1736
+   |
+   = help: Use the loop variable directly
+
+ℹ Safe fix
+71 71 | 
+72 72 |     # PLR1736
+73 73 |     for index, list_item in enumerate(some_list, start=0):
+74    |-        print(some_list[index])
+   74 |+        print(list_item)
+75 75 | 
+76 76 |     # PLR1736
+77 77 |     for index, list_item in enumerate(some_list):
+
+unnecessary_list_index_lookup.py:78:15: PLR1736 [*] List index lookup in `enumerate()` loop
+   |
+76 |     # PLR1736
+77 |     for index, list_item in enumerate(some_list):
+78 |         print(some_list[index])
+   |               ^^^^^^^^^^^^^^^^ PLR1736
+   |
+   = help: Use the loop variable directly
+
+ℹ Safe fix
+75 75 | 
+76 76 |     # PLR1736
+77 77 |     for index, list_item in enumerate(some_list):
+78    |-        print(some_list[index])
+   78 |+        print(list_item)