Correction to unit definitions, use CDS standard.

setup.py

@@ -4,7 +4,7 @@
 
 setup(
     name="voevent-parse",
-    version="0.9.0",
+    version="0.9.1",
     packages=['voeventparse', 'voeventparse.tests', 'voeventparse.tests.resources'],
     package_data={'voeventparse':['tests/resources/*.xml']},
     description="Convenience routines for parsing and manipulation of "

voeventparse/definitions.py

@@ -10,14 +10,14 @@
 # ############################
 # Some useful string defs namespaced via a class container:
 
-class roles(object):
+class roles:
     observation = 'observation'
     prediction = 'prediction'
     utility = 'utility'
     test = 'test'
 
 
-class sky_coord_system(object):
+class sky_coord_system:
     """
     Common coordinate system identifiers. See also :class:`.Position2D`.
 
@@ -53,12 +53,16 @@ class observatory_location(object):
     geolunar = 'GEOLUN'
 
 
-class coord_units(object):
-    """Handy tags listing the unit names used by voeventparse."""
-    degrees = 'degrees'
+class units:
+    """
+    Unit abbreviations as defined by CDS (incomplete listing)
+
+    cf http://vizier.u-strasbg.fr/doc/catstd-3.2.htx
+    """
+    degrees = 'deg'
 
 
-class cite_types(object):
+class cite_types:
     """Possible types of :func:`.Citation`"""
     followup = 'followup'
     supersedes = 'supersedes'

voeventparse/misc.py

@@ -16,10 +16,11 @@ class Position2D(namedtuple('Position2D', 'ra dec err units system')):
         ra (float): Right ascension.
         dec (float): Declination
         err (float): Error radius.
-        units (:class:`.definitions.coord_units`): Coordinate units
+        units (str): Coordinate units, cf :class:`.definitions.units`
             e.g. degrees, radians.
-        system (:class:`.definitions.sky_coord_system`): Co-ordinate system
-            e.g. UTC-FK5-GEO
+        system (str): Co-ordinate system, e.g. UTC-FK5-GEO
+            cf :class:`.definitions.sky_coord_system`
+
     """
     pass  # Just wrapping a namedtuple so we can assign a docstring.