Changed the type of __path__ from Iterable[str] to `MutableSequen…

…ce[str]`. Both are correct, but the latter is more precise. This addresses #10058. (#10062)
microsoft · Mar 11, 2025 · ae5479d · ae5479d
1 parent bad0c19
commit ae5479d
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Showing 5 changed files with 15 additions and 8 deletions.
diff --git a/packages/pyright-internal/src/analyzer/binder.ts b/packages/pyright-internal/src/analyzer/binder.ts
@@ -286,7 +286,7 @@ export class Binder extends ParseTreeWalker {
                 this._addImplicitSymbolToCurrentScope('__loader__', node, 'Any');
                 this._addImplicitSymbolToCurrentScope('__package__', node, 'str | None');
                 this._addImplicitSymbolToCurrentScope('__spec__', node, 'Any');
-                this._addImplicitSymbolToCurrentScope('__path__', node, 'Iterable[str]');
+                this._addImplicitSymbolToCurrentScope('__path__', node, 'MutableSequence[str]');
                 this._addImplicitSymbolToCurrentScope('__file__', node, 'str');
                 this._addImplicitSymbolToCurrentScope('__cached__', node, 'str');
                 this._addImplicitSymbolToCurrentScope('__dict__', node, 'Dict[str, Any]');

diff --git a/packages/pyright-internal/src/analyzer/declaration.ts b/packages/pyright-internal/src/analyzer/declaration.ts
@@ -46,7 +46,14 @@ export const enum DeclarationType {
     Alias,
 }
 
-export type IntrinsicType = 'Any' | 'str' | 'str | None' | 'int' | 'Iterable[str]' | 'type[self]' | 'Dict[str, Any]';
+export type IntrinsicType =
+    | 'Any'
+    | 'str'
+    | 'str | None'
+    | 'int'
+    | 'MutableSequence[str]'
+    | 'type[self]'
+    | 'Dict[str, Any]';
 
 export interface DeclarationBase {
     // Category of this symbol (function, variable, etc.).

diff --git a/packages/pyright-internal/src/analyzer/typeEvaluator.ts b/packages/pyright-internal/src/analyzer/typeEvaluator.ts
@@ -22164,11 +22164,11 @@ export function createTypeEvaluator(
                         return { type: intType };
                     }
 
-                    if (declaration.intrinsicType === 'Iterable[str]') {
-                        const iterableType = getBuiltInType(declaration.node, 'Iterable');
-                        if (isInstantiableClass(iterableType)) {
+                    if (declaration.intrinsicType === 'MutableSequence[str]') {
+                        const sequenceType = getBuiltInType(declaration.node, 'MutableSequence');
+                        if (isInstantiableClass(sequenceType)) {
                             return {
-                                type: ClassType.cloneAsInstance(ClassType.specialize(iterableType, [strType])),
+                                type: ClassType.cloneAsInstance(ClassType.specialize(sequenceType, [strType])),
                             };
                         }
                     }

diff --git a/packages/pyright-internal/src/tests/samples/import1.py b/packages/pyright-internal/src/tests/samples/import1.py
@@ -1,7 +1,7 @@
 # This sample tests the type analyzer's handling of the built-in
 # __import__ function.
 
-reveal_type(__path__, expected_text="Iterable[str]")
+reveal_type(__path__, expected_text="MutableSequence[str]")
 
 # This should not generate a type error.
 __path__ = __import__("pkgutil").extend_path(__path__, __name__)
diff --git a/packages/pyright-internal/src/tests/samples/module3.py b/packages/pyright-internal/src/tests/samples/module3.py
@@ -6,7 +6,7 @@
 reveal_type(datetime.__loader__, expected_text="Any")
 reveal_type(datetime.__package__, expected_text="str | None")
 reveal_type(datetime.__spec__, expected_text="Any")
-reveal_type(datetime.__path__, expected_text="Iterable[str]")
+reveal_type(datetime.__path__, expected_text="MutableSequence[str]")
 reveal_type(datetime.__file__, expected_text="str")
 reveal_type(datetime.__cached__, expected_text="str")
 reveal_type(datetime.__dict__, expected_text="dict[str, Any]")