Merge pull request #4213 from asottile/flake8_master_fixes

Fixes for flake8 master

doc/en/example/py2py3/test_py2.py

@@ -1,6 +1,5 @@
-
 def test_exception_syntax():
     try:
         0 / 0
     except ZeroDivisionError, e:
-        pass
+        assert e

doc/en/example/py2py3/test_py3.py

@@ -2,4 +2,4 @@ def test_exception_syntax():
     try:
         0 / 0
     except ZeroDivisionError as e:
-        pass
+        assert e

src/_pytest/assertion/rewrite.py

@@ -706,10 +706,9 @@ class AssertionRewriter(ast.NodeVisitor):
                     setattr(node, name, new)
                 elif (
                     isinstance(field, ast.AST)
-                    and
                     # Don't recurse into expressions as they can't contain
                     # asserts.
-                    not isinstance(field, ast.expr)
+                    and not isinstance(field, ast.expr)
                 ):
                     nodes.append(field)
 

src/_pytest/pathlib.py

@@ -245,8 +245,8 @@ def make_numbered_dir_with_cleanup(root, prefix, keep, lock_timeout):
             p = make_numbered_dir(root, prefix)
             lock_path = create_cleanup_lock(p)
             register_cleanup_lock_removal(lock_path)
-        except Exception as e:
-            pass
+        except Exception as exc:
+            e = exc
         else:
             consider_lock_dead_if_created_before = p.stat().st_mtime - lock_timeout
             cleanup_numbered_dir(