clean up some test code and apply some safety fixes

Cython/TestUtils.py

@@ -8,13 +8,15 @@ import unittest
 import os, sys
 import tempfile
 
+
 class NodeTypeWriter(TreeVisitor):
     def __init__(self):
         super(NodeTypeWriter, self).__init__()
         self._indents = 0
         self.result = []
+
     def visit_Node(self, node):
-        if len(self.access_path) == 0:
+        if not self.access_path:
             name = u"(root)"
         else:
             tip = self.access_path[-1]
@@ -29,6 +31,7 @@ class NodeTypeWriter(TreeVisitor):
         self.visitchildren(node)
         self._indents -= 1
 
+
 def treetypes(root):
     """Returns a string representing the tree by class names.
     There's a leading and trailing whitespace so that it can be
@@ -38,6 +41,7 @@ def treetypes(root):
     w.visit(root)
     return u"\n".join([u""] + w.result + [u""])
 
+
 class CythonTest(unittest.TestCase):
 
     def setUp(self):
@@ -110,6 +114,7 @@ class CythonTest(unittest.TestCase):
         except:
             self.fail(str(sys.exc_info()[1]))
 
+
 class TransformTest(CythonTest):
     """
     Utility base class for transform unit tests. It is based around constructing
@@ -134,7 +139,6 @@ class TransformTest(CythonTest):
     Plans: One could have a pxd dictionary parameter to run_pipeline.
     """
 
-
     def run_pipeline(self, pipeline, pyx, pxds={}):
         tree = self.fragment(pyx, pxds).root
         # Run pipeline
@@ -166,6 +170,7 @@ class TreeAssertVisitor(VisitorTransform):
 
     visit_Node = VisitorTransform.recurse_to_children
 
+
 def unpack_source_tree(tree_file, dir=None):
     if dir is None:
         dir = tempfile.mkdtemp()
@@ -176,7 +181,8 @@ def unpack_source_tree(tree_file, dir=None):
         lines = f.readlines()
     finally:
         f.close()
-    f = None
+    del f
+    try:
         for line in lines:
             if line[:5] == '#####':
                 filename = line.strip().strip('#').strip().replace('/', os.path.sep)
@@ -184,13 +190,15 @@ def unpack_source_tree(tree_file, dir=None):
                 if not os.path.exists(os.path.dirname(path)):
                     os.makedirs(os.path.dirname(path))
                 if cur_file is not None:
-                cur_file.close()
+                    f, cur_file = cur_file, None
+                    f.close()
                 cur_file = open(path, 'w')
             elif cur_file is not None:
                 cur_file.write(line)
             elif line.strip() and not line.lstrip().startswith('#'):
                 if line.strip() not in ('"""', "'''"):
                     header.append(line)
+    finally:
         if cur_file is not None:
             cur_file.close()
     return dir, ''.join(header)