Add a new error for the Python 3 porting checker, `import-star-module-level`.

This error is used when a star import is detected in another scope than the
module level, which is an error on Python 3. Using this will emit a
SyntaxWarning on Python 2.

3 files changed, 24 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 800e8c4..745cb18 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -187,6 +187,11 @@ ChangeLog for Pylint
 
     * Detect a couple of objects which can't be base classes (bool,
       slice, range and memoryview, which weren't detected until now).
+
+    * Add a new error for the Python 3 porting checker, `import-star-module-level`,
+      which is used when a star import is detected in another scope than the
+      module level, which is an error on Python 3. Using this will emit a
+      SyntaxWarning on Python 2.
       
 
 
diff --git a/pylint/checkers/python3.py b/pylint/checkers/python3.py
index 95aa3a7..6738ec6 100644
--- a/pylint/checkers/python3.py
+++ b/pylint/checkers/python3.py
@@ -130,6 +130,11 @@ class Python3Checker(checkers.BaseChecker):
                   {'scope': WarningScope.NODE,
                    'maxversion': (3, 0),
                    'old_names': [('W0333', 'backtick')]}),
+        'E1609': ('Import * only allowed at module level',
+                  'import-star-module-level',
+                  'Used when the import star syntax is used somewhere '
+                  'else than the module level.',
+                  {'maxversion': (3, 0)}),
         'W1601': ('apply built-in referenced',
                   'apply-builtin',
                   'Used when the apply built-in function is referenced '
@@ -403,7 +408,7 @@ class Python3Checker(checkers.BaseChecker):
     def visit_print(self, node):
         self.add_message('print-statement', node=node)
 
-    @utils.check_messages('no-absolute-import')
+    @utils.check_messages('no-absolute-import', 'import-star-module-level')
     def visit_from(self, node):
         if node.modname == '__future__':
             for name, _ in node.names:
@@ -413,6 +418,9 @@ class Python3Checker(checkers.BaseChecker):
                     self._future_absolute_import = True
         elif not self._future_absolute_import:
             self.add_message('no-absolute-import', node=node)
+        if node.names[0][0] == '*':
+            if not isinstance(node.scope(), astroid.Module):
+                self.add_message('import-star-module-level', node=node)
 
     @utils.check_messages('no-absolute-import')
     def visit_import(self, node):
diff --git a/pylint/test/unittest_checker_python3.py b/pylint/test/unittest_checker_python3.py
index 7d7b052..57a4459 100644
--- a/pylint/test/unittest_checker_python3.py
+++ b/pylint/test/unittest_checker_python3.py
@@ -258,6 +258,16 @@ class Python3CheckerTest(testutils.CheckerTestCase):
             for module in (module_import, module_from):
                 self.walk(module)
 
+    def test_import_star_module_level(self):
+        node = test_utils.extract_node('''
+        def test():
+            from lala import * #@
+        ''')
+        absolute = testutils.Message('no-absolute-import', node=node)
+        star = testutils.Message('import-star-module-level', node=node)
+        with self.assertAddsMessages(absolute, star):
+            self.checker.visit_from(node)
+
     def test_division(self):
         node = test_utils.extract_node('3 / 2  #@')
         message = testutils.Message('old-division', node=node)