Added support for PEP 562's __getattr__ function.

server/src/analyzer/typeEvaluator.ts

@@ -6770,11 +6770,20 @@ export function createTypeEvaluator(importLookup: ImportLookup): TypeEvaluator {
 
                 // If we were able to resolve the import, report the error as
                 // an unresolved symbol.
-                if (importLookup(resolvedPath)) {
-                    addError(
-                        `'${ node.name.value }' is unknown import symbol`,
-                        node.name
-                    );
+                const importLookupInfo = importLookup(resolvedPath);
+                if (importLookupInfo) {
+                    const fileInfo = getFileInfo(node);
+
+                    // Handle PEP 562 support for module-level __getattr__ function,
+                    // introduced in Python 3.7.
+                    if (fileInfo.executionEnvironment.pythonVersion < PythonVersion.V37 ||
+                            !importLookupInfo.symbolTable.get('__getattr__')) {
+
+                        addError(
+                            `'${ node.name.value }' is unknown import symbol`,
+                            node.name
+                        );
+                    }
                 }
             }
 

server/src/tests/checker.test.ts

@@ -980,6 +980,11 @@ test('Import7', () => {
     validateResults(analysisResults, 2);
 });
 
+test('Import9', () => {
+    const analysisResults = TestUtils.typeAnalyzeSampleFiles(['import9.py']);
+    validateResults(analysisResults, 0);
+});
+
 test('Overload1', () => {
     const analysisResults = TestUtils.typeAnalyzeSampleFiles(['overload1.py']);
     validateResults(analysisResults, 2);

server/src/tests/samples/import8.py

@@ -0,0 +1,9 @@
+# This sample is imported by import9.py.
+
+# Implement __getattr__ function as described in PEP 562.
+
+def __getattr__(name: str):
+    return None
+
+
+

server/src/tests/samples/import9.py

@@ -0,0 +1,8 @@
+# This sample tests support for PEP 562's __getattr__ function.
+
+# This should not generate an error because import9 has
+# a __getattr__ method.
+from .import8 import foo
+
+foo()
+