Editing Features
The ArcGIS API for Python makes programmatic editing of features a breeze. The edit_features() method on FeatureLayer object can be used for the same. In the example below, we see how to add, update and delete features from a point feature layer
#connect to GIS
from arcgis.gis import GIS
from IPython.display import display
gis = GIS("portal url", 'username', 'password')
#search for the feature layer named Ports along west coast
portal_item = gis.content.get('6a8766e14d3d41cfb8fc8d4d8974f16d')
portal_item
Feature Layer Collection by api_data_owner
#access the item's feature layers
ports_layer = portal_item.layers[0]
ports_layer
Query the features¶
Let us query the features on this layer
#query all the features and display it on a map
ports_fset = ports_layer.query() #an empty query string will return all
#the features or the first 1000 which ever is smaller
The sdf property of FeatureSet class is a powerful way to visualize all the features as a pandas dataframe table.
ports_fset.sdf
Check if the layer can be edited¶
To enable a feature layer to be edited, the edit capability needs to be turned on for the item. This can be verified by accessing the capabilities property on the FeatureLayer object:
ports_layer.properties.capabilities
Editing features¶
Updating features¶
From the dataframe above, we notice the short_form field of San Francisco port has a typo. We can update this by calling the edit_features() method on the ports_flayer FeatureLayer object. The edit_features() method accepts a Feature object with correct parameters set.
ports_features = ports_fset.features
# select San Francisco feature
sfo_feature = [f for f in ports_features if f.attributes['port_name']=='SAN FRANCISCO'][0]
sfo_feature.attributes
As we can see above, the short_form attribute should be changed to SFO. Let us edit that and store it as a new Feature object
sfo_edit = sfo_feature
sfo_edit.attributes['short_form'] = 'SFO'
display(sfo_edit)
Now let us send this feature object to the edit_features() method and edit the original feature layer
update_result = ports_flayer.edit_features(updates=[sfo_edit])
update_result
Adding features¶
From the data frame, we also notice that 'Los Angeles', an important port is missing. We can add this to the original layer by calling the edit_features() method and passing a dictionary representation of the feature
# construct a Feature object for Los Angeles.
la_dict = {"attributes":
{"latitude": 33.75,
"longitude": -118.25,
"country": "US",
"harborsize": "L",
"label_position": "SW",
"port_name": "LOS ANGELES",
"short_form": "LAX"},
"geometry":
{"x": -13044788.958999995, "y": 3857756.351200014}}
add_result = ports_flayer.edit_features(adds = [la_dict])
add_result
Deleting features¶
From the data frame, we notice 'Redlands', a land locked city is wrongly added as a port. We can remove it by calling the edit_features() method and passing the object id of the feature we want to be remove to the deletes parameter.
# find object id for Redlands
Redlands_feature = [f for f in ports_features if f.attributes['port_name'] == 'REDLANDS'][0]
Redlands_objid = Redlands_feature.get_value('objectid')
Redlands_objid
type(Redlands_objid)
# pass the object id as a string to the delete parameter
delete_result = ports_flayer.edit_features(deletes=str(Redlands_objid))
delete_result
Check results of edit operations¶
We have successfully added, removed and edited features. Let us query the layer once again and display the resutls as a dataframe and verify them.
ports_fset_edited = ports_flayer.query()
ports_fset_edited.sdf
Thus, we no longer see 'Redlands' which we deleted. We see a new objectid of 23 corresponding to Los Angeles that we added. Also the short_form of San Francisco is corrected to 'SFO'.
The edits we performed on the features are persisted in the feature layer and will reflect in all clients accessing it.