Clean up sys.path entry.

IPython/lib/tests/test_deepreload.py

@@ -11,6 +11,7 b' import sys'
 import nose.tools as nt
 
 from IPython.testing import decorators as dec
+from IPython.utils.syspathcontext import prepended_to_syspath
 from IPython.utils.tempdir import TemporaryDirectory
 from IPython.lib.deepreload import reload as dreload
 
@@ -33,20 +34,20 b' def test_deepreload_numpy():'
 def test_deepreload():
     "Test that dreload does deep reloads and skips excluded modules."
     with TemporaryDirectory() as tmpdir:
-        sys.path.insert(0, tmpdir)
-        with open(os.path.join(tmpdir, 'A.py'), 'w') as f:
-            f.write("class Object(object):\n    pass\n")
-        with open(os.path.join(tmpdir, 'B.py'), 'w') as f:
-            f.write("import A\n")
-        import A
-        import B
-
-        # Test that A is not reloaded.
-        obj = A.Object()
-        dreload(B, exclude=['A'])
-        nt.assert_true(isinstance(obj, A.Object))
-
-        # Test that A is reloaded.
-        obj = A.Object()
-        dreload(B)
-        nt.assert_false(isinstance(obj, A.Object))
+        with prepended_to_syspath(tmpdir):
+            with open(os.path.join(tmpdir, 'A.py'), 'w') as f:
+                f.write("class Object(object):\n    pass\n")
+            with open(os.path.join(tmpdir, 'B.py'), 'w') as f:
+                f.write("import A\n")
+            import A
+            import B
+
+            # Test that A is not reloaded.
+            obj = A.Object()
+            dreload(B, exclude=['A'])
+            nt.assert_true(isinstance(obj, A.Object))
+
+            # Test that A is reloaded.
+            obj = A.Object()
+            dreload(B)
+            nt.assert_false(isinstance(obj, A.Object))