more tests and flake8

src/RestrictedPython/transformer.py

@@ -452,10 +452,8 @@ def check_import_names(self, node):
         => 'from _a import x' is ok, because '_a' is not added to the scope.
         """
         if (isinstance(node, ast.ImportFrom)
-            and not node.module == '__future__'
-            and any(
-                [name.startswith('_') for name in node.module.split('.')]
-                )):
+                and not node.module == '__future__'
+                and any([name.startswith('_') for name in node.module.split('.')])):  # NOQA: E501
             self.error(node, 'module name starts "_", which is forbidden.')
 
         for name in node.names:

tests/transformer/test_import.py

@@ -71,6 +71,15 @@ def test_RestrictingNodeTransformer__visit_Import__6_3(c_exec):
     )
 
 
+@pytest.mark.parametrize(*c_exec)
+def test_RestrictingNodeTransformer__visit_Import__6_4(c_exec):
+    """It allows importing from a module starting with `_`."""
+    result = c_exec('from _a._b import m as x')
+    assert result.errors == (
+        'Line 1: module name starts "_", which is forbidden.',
+    )
+
+
 @pytest.mark.parametrize(*c_exec)
 def test_RestrictingNodeTransformer__visit_Import__7(c_exec):
     """It denies importing from a module as something starting with `_`."""
@@ -106,3 +115,11 @@ def test_RestrictingNodeTransformer__visit_Import_star__2(c_exec):
     result = c_exec('from a import *')
     assert result.errors == ('Line 1: "*" imports are not allowed.',)
     assert result.code is None
+
+
+@pytest.mark.parametrize(*c_exec)
+def test_RestrictingNodeTransformer__visit_Import__future__1(c_exec):
+    """It allows importing from a module."""
+    result = c_exec('from __future__ import print_function')
+    assert result.errors == ()
+    assert result.code is not None