Merge pull request #1259 from kgoebber/update_declare_plots

Update PlotObs for time and station dimension naming

src/metpy/plots/declarative.py

@@ -1410,14 +1410,21 @@ def name(self):
     @property
     def obsdata(self):
         """Return the internal cached data."""
-        time_vars = ['valid', 'time', 'valid_time']
-        stn_vars = ['station', 'stn']
+        time_vars = ['valid', 'time', 'valid_time', 'date_time', 'date']
+        stn_vars = ['station', 'stn', 'station_id', 'stid']
         if getattr(self, '_obsdata', None) is None:
-            for dim_name in list(self.data):
-                if dim_name in time_vars:
-                    dim_time = dim_name
-                elif dim_name in stn_vars:
-                    dim_stn = dim_name
+            dim_times = [time_var for time_var in time_vars if time_var in list(self.data)]
+            dim_stns = [stn_var for stn_var in stn_vars if stn_var in list(self.data)]
+            if not dim_times:
+                raise AttributeError('Time variable not found. Valid variable names are:'
+                                     f'{time_vars}')
+            else:
+                dim_time = dim_times[0]
+            if not dim_stns:
+                raise AttributeError('Station variable not found. Valid variable names are: '
+                                     f'{stn_vars}')
+            else:
+                dim_stn = dim_stns[0]
             if self.level is not None:
                 level_subset = self.data.pressure == self.level.m
                 self._obsdata = self.data[level_subset]
@@ -1467,7 +1474,7 @@ def _build(self):
         lon, lat, data = self.plotdata
 
         # Use the cartopy map projection to transform station locations to the map and
-        # then refine the number of stations plotted by setting a 300km radius
+        # then refine the number of stations plotted by setting a radius
         if self.parent._proj_obj == ccrs.PlateCarree():
             scale = 1.
         else:

tests/plots/test_declarative.py

@@ -558,6 +558,68 @@ def test_declarative_upa_obs():
     return pc.figure
 
 
+def test_attribute_error_time():
+    """Make sure we get a useful error when the time variable is not found."""
+    data = pd.read_csv(get_test_data('SFC_obs.csv', as_file_obj=False),
+                       infer_datetime_format=True, parse_dates=['valid'])
+    data.rename(columns={'valid': 'vtime'}, inplace=True)
+
+    obs = PlotObs()
+    obs.data = data
+    obs.time = datetime(1993, 3, 12, 12)
+    obs.level = None
+    obs.fields = ['tmpf']
+    obs.time_window = timedelta(minutes=15)
+
+    # Panel for plot with Map features
+    panel = MapPanel()
+    panel.layout = (1, 1, 1)
+    panel.projection = ccrs.PlateCarree()
+    panel.area = 'in'
+    panel.layers = ['states']
+    panel.plots = [obs]
+    panel.title = f'Surface Observations for {obs.time}'
+
+    # Bringing it all together
+    pc = PanelContainer()
+    pc.size = (10, 10)
+    pc.panels = [panel]
+
+    with pytest.raises(AttributeError):
+        pc.draw()
+
+
+def test_attribute_error_station():
+    """Make sure we get a useful error when the station variable is not found."""
+    data = pd.read_csv(get_test_data('SFC_obs.csv', as_file_obj=False),
+                       infer_datetime_format=True, parse_dates=['valid'])
+    data.rename(columns={'station': 'location'}, inplace=True)
+
+    obs = PlotObs()
+    obs.data = data
+    obs.time = datetime(1993, 3, 12, 12)
+    obs.level = None
+    obs.fields = ['tmpf']
+    obs.time_window = timedelta(minutes=15)
+
+    # Panel for plot with Map features
+    panel = MapPanel()
+    panel.layout = (1, 1, 1)
+    panel.projection = ccrs.PlateCarree()
+    panel.area = 'in'
+    panel.layers = ['states']
+    panel.plots = [obs]
+    panel.title = f'Surface Observations for {obs.time}'
+
+    # Bringing it all together
+    pc = PanelContainer()
+    pc.size = (10, 10)
+    pc.panels = [panel]
+
+    with pytest.raises(AttributeError):
+        pc.draw()
+
+
 def test_save():
     """Test that our saving function works."""
     pc = PanelContainer()