fix some pylint findings

Cython/Compiler/Visitor.py

@@ -77,9 +77,8 @@ class TreeVisitor(object):
         self.access_path = []
 
     def dump_node(self, node, indent=0):
-        ignored = list(node.child_attrs or []) + [u'child_attrs', u'pos',
-                                            u'gil_message', u'cpp_message',
-                                            u'subexprs']
+        ignored = list(node.child_attrs or []) + [
+            u'child_attrs', u'pos', u'gil_message', u'cpp_message', u'subexprs']
         values = []
         pos = getattr(node, 'pos', None)
         if pos:
@@ -93,7 +92,7 @@ class TreeVisitor(object):
         for attr in attribute_names:
             if attr in ignored:
                 continue
-            if attr.startswith(u'_') or attr.endswith(u'_'):
+            if attr.startswith('_') or attr.endswith('_'):
                 continue
             try:
                 value = getattr(node, attr)
@@ -108,8 +107,7 @@ class TreeVisitor(object):
             else:
                 value = repr(value)
             values.append(u'%s = %s' % (attr, value))
-        return u'%s(%s)' % (node.__class__.__name__,
-                           u',\n    '.join(values))
+        return u'%s(%s)' % (node.__class__.__name__, u',\n    '.join(values))
 
     def _find_node_path(self, stacktrace):
         import os.path
@@ -129,7 +127,6 @@ class TreeVisitor(object):
         return (last_traceback, nodes)
 
     def _raise_compiler_error(self, child, e):
-        import sys
         trace = ['']
         for parent, attribute, index in self.access_path:
             node = getattr(parent, attribute)
@@ -389,7 +386,7 @@ class EnvTransform(CythonTransform):
     def visit_CArgDeclNode(self, node):
         # default arguments are evaluated in the outer scope
         if node.default:
-            attrs = [ attr for attr in node.child_attrs if attr != 'default' ]
+            attrs = [attr for attr in node.child_attrs if attr != 'default']
             self.visitchildren(node, attrs)
             self.enter_scope(node, self.current_env().outer_scope)
             self.visitchildren(node, ('default',))