Minor fixes to examples

* Fix typo in authenticate
* Add comments to head command
* Fix name of head method
* Use find_resource_cls for lists

Change-Id: If4bb485088460151916e1d2b9b5fe80ad150dcff

examples/authenticate.py

@@ -14,7 +14,7 @@
 Authentication example
 
 To authenticate you must have the environment variables set or use the
-command line options.  This is a good example to start wtih because once
+command line options.  This is a good example to start with because once
 you know you can authenticate, you can perform other operations that
 require authentication.  Refer to the example common.py for the environment
 variables or command line options to use.

examples/head.py

@@ -10,13 +10,21 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+"""
+Example Head Command
+
+For example:
+    python -m examples.head openstack/image/v1/image.py \
+        --data 9d7d22d0-7d43-481f-a7eb-d93ea2791409
+"""
+
 import sys
 
 from examples import common
 from examples import session
 
 
-def run_get(opts):
+def run_head(opts):
     sess = session.make_session(opts)
     cls = common.find_resource_cls(opts)
     data = common.get_data_option(opts)
@@ -28,4 +36,4 @@ def run_get(opts):
 
 if __name__ == "__main__":
     opts = common.setup()
-    sys.exit(common.main(opts, run_get))
+    sys.exit(common.main(opts, run_head))

examples/list.py

@@ -16,19 +16,9 @@ from examples import common
 from examples import session
 
 
-def make_resource(opts):
-    argument = opts.argument
-    args = argument.rpartition('.')
-    from_str = args[0]
-    class_str = args[2]
-    __import__(from_str)
-    mod = sys.modules[from_str]
-    return getattr(mod, class_str)
-
-
 def run_list(opts):
     sess = session.make_session(opts)
-    cls = make_resource(opts)
+    cls = common.find_resource_cls(opts)
     for obj in cls.list(sess):
         print(str(obj))
     return