add some simple context manager aka "with" test

context-managers.py

@@ -0,0 +1,29 @@
+from contextlib import contextmanager
+import os
+
+
+@contextmanager
+def working_directory(path):
+    current_dir = os.getcwd()
+    os.chdir(path)
+    try:
+        yield
+    finally:
+        os.chdir(current_dir)
+
+
+@contextmanager
+def just_a_test():
+    try:
+        print "just trying..."
+        yield
+    finally:
+        print "finally!"
+
+
+with working_directory("/tmp"), just_a_test():
+    # do something within data/stuff
+    print os.getcwd()
+
+# here I am back again in the original working directory
+print os.getcwd()