Add example

README.md

@@ -46,6 +46,53 @@ which contains metadata information in addition to the observed data series.
 Modelling products are returned as the data series only, which is either a pandas
 Series or DataFrame, or xarray for multi-dimensional data.
 
+
+```python
+# Example getting hourly air temperature for the latest months from
+# SMHI station Stockholm-Observatoriekullen A  (number 98230)
+from sondera.clients.smhi import MetObsClient, ParametersMetObs
+
+client = MetObsClient()
+# For the parameter we can pass either the ParametersMetObs enum
+# or simply the SMHI integer id (which is 1 for hourly air temperature)
+air_temp = client.get_observations(parameter=ParametersMetObs.TemperatureAirHour,
+                         station= 98230,
+                         period= 'latest-months')
+
+# observations are stored under "data" attribute as a pandas.Series
+air_temp.data.head(5)
+timestamp
+2021-12-31 01:00:00    4.9
+2021-12-31 02:00:00    4.2
+2021-12-31 03:00:00    3.5
+2021-12-31 04:00:00    3.1
+2021-12-31 05:00:00    3.0
+Name: TemperatureAirHour, dtype: float64
+
+# additional data, such as quality tags are stored under "aux_data"
+air_temp.aux_data.head(5)
+                    quality
+timestamp                  
+2021-12-31 01:00:00       G
+2021-12-31 02:00:00       G
+2021-12-31 03:00:00       G
+2021-12-31 04:00:00       G
+2021-12-31 05:00:00       G
+
+# information on the station is also available, such as name, id, coordinates,
+# and history
+air_temp.station
+Station(name='Stockholm-Observatoriekullen A', id=98230, agency='SMHI', 
+        position=Coordinate(y=59.341681, x=18.054928, z=43.133, epsg_xy=4326, epsg_z=5613),
+        station_type=<StationType.MetStation: 2>, active_station=True, 
+        active_period=[Timestamp('1996-10-01 00:00:00'), Timestamp('2022-05-10 07:00:00')],
+        last_updated=Timestamp('2022-05-10 07:00:00'), station_info={}, 
+        position_history=[{'from': Timestamp('1996-10-01 00:00:00'), 
+                           'to': Timestamp('2022-05-10 07:00:00'), 
+                           'position': Coordinate(y=59.341681, x=18.054928, z=43.133,
+                                                  epsg_xy=4326, epsg_z=5613)}])
+```
+
 ## Feedback and issues
 
 Please report issues here: https://github.com/rhkarls/sondera/issues