Fixes to disallowed_imports

docs/changelog.md

@@ -3,7 +3,7 @@
 ## Unreleased
 
 - Add `disallowed_imports` configuration option to disallow
-  imports of specific modules (#645)
+  imports of specific modules (#645, #646)
 - Consider an annotated assignment without a value to be
   an exported name (#644)
 - Improve the location where `missing_parameter_annotation`

pyanalyze/name_check_visitor.py

@@ -2320,15 +2320,20 @@ def check_deprecation(self, node: ast.AST, value: Value) -> bool:
 
     # Imports
 
-    def check_for_disallowed_import(self, node: ast.AST, name: str) -> None:
-        print("CHECK", name)
+    def check_for_disallowed_import(
+        self, node: ast.AST, name: str, *, check_parents: bool = True
+    ) -> None:
         disallowed = self.options.get_value_for(DisallowedImports)
-        if name in disallowed:
-            self._show_error_if_checking(
-                node,
-                f"Disallowed import of module {name!r}",
-                error_code=ErrorCode.disallowed_import,
-            )
+        parts = name.split(".") if check_parents else [name]
+        for i in range(len(parts)):
+            name_to_check = ".".join(parts[: i + 1])
+            if name_to_check in disallowed:
+                self._show_error_if_checking(
+                    node,
+                    f"Disallowed import of module {name!r}",
+                    error_code=ErrorCode.disallowed_import,
+                )
+                break
 
     def visit_Import(self, node: ast.Import) -> None:
         self.generic_visit(node)
@@ -2434,7 +2439,7 @@ def visit_ImportFrom(self, node: ast.ImportFrom) -> None:
                 else:
                     error_node = node
                 self.check_for_disallowed_import(
-                    error_node, f"{node.module}.{alias.name}"
+                    error_node, f"{node.module}.{alias.name}", check_parents=False
                 )
 
         self._maybe_record_usages_from_import(node)

pyanalyze/test.toml

@@ -16,4 +16,5 @@ class_attribute_transformers = [
 disallowed_imports = [
     "getopt",
     "email.quoprimime",
+    "xml",
 ]

pyanalyze/test_import.py

@@ -47,38 +47,45 @@ class TestDisallowedImport(TestNameCheckVisitorBase):
     @assert_passes()
     def test_top_level(self):
         import getopt  # E: disallowed_import
+        import xml.etree.ElementTree  # E: disallowed_import
 
         from getopt import GetoptError  # E: disallowed_import
 
-        print(getopt, GetoptError)  # shut up flake8
+        print(getopt, GetoptError, xml)  # shut up flake8
 
         def capybara():
             import getopt  # E: disallowed_import
             from getopt import GetoptError  # E: disallowed_import
+            import xml.etree.ElementTree  # E: disallowed_import
 
-            print(getopt, GetoptError)
+            print(getopt, GetoptError, xml)
 
     @assert_passes()
     def test_nested(self):
         import email.quoprimime  # E: disallowed_import
+        import email.base64mime  # ok
         from email.quoprimime import unquote  # E: disallowed_import
+        from xml.etree import ElementTree  # E: disallowed_import
 
-        print(email, unquote)
+        print(email, unquote, ElementTree)
 
         def capybara():
             import email.quoprimime  # E: disallowed_import
+            import email.base64mime  # ok
             from email.quoprimime import unquote  # E: disallowed_import
-            from email import quoprimime  # E: disallowed_import
+            from xml.etree import ElementTree  # E: disallowed_import
 
-            print(email, unquote, quoprimime)
+            print(email, unquote, ElementTree)
 
     @assert_passes()
     def test_import_from(self):
         from email import quoprimime  # E: disallowed_import
+        from email import base64mime  # ok
 
-        print(quoprimime)
+        print(quoprimime, base64mime)
 
         def capybara():
             from email import quoprimime  # E: disallowed_import
+            from email import base64mime  # ok
 
-            print(quoprimime)
+            print(quoprimime, base64mime)