摘要
FeatureSet 对象是要素类的轻量级表示。 它们是一种既包含方案又包含数据的数据元素。 而且，FeatureSet 对象也表示通过服务器发送和接收要素数据的方式。
说明
当使用 Feature Set 对象时，请记住以下几点：
- 使用 FeatureSet 对象作为修改输入的工具或函数的输入（例如计算字段或 UpdateCursor），它将修改原始要素类。
- 将新要素类加载到 FeatureSet 对象中不会覆盖原始要素类。 load 方法只会更改对要素类的引用，而不会更改原始要素类。
语法
FeatureSet ({table_path}, {where_clause}, {time_filter}, {renderer}, {is_renderer}, {geojson_geometry_type})| 参数 | 说明 | 数据类型 |
table_path | The features to load into the FeatureSet object. The input can be a catalog path to a feature class, a URL to a hosted feature layer, a JSON with the syntax {"url":"<url>", "serviceToken":"<ServiceToken>"} to load data from external sources that require an access token, an Esri (featureSet) JSON string, or a GeoJSON string. Esri JSON and GeoJSON are standards for encoding feature (geometry and attribute) data as a .json file. | String |
where_clause | An SQL expression used to select a subset of records. For more information about SQL syntax, see SQL reference for query expressions used in ArcGIS. (默认值为 None) | String |
time_filter | The time instant or the time extent to query. The time filter can only be applied to hosted feature layers, and the layer must be time enabled. Format a time instant as a string, for example, "1199145600000" (1 Jan 2008 00:00:00 GMT). Format a time extent as a comma-delimited string, for example, "1199145600000, 1230768000000" (1 Jan 2008 00:00:00 GMT to 1 Jan 2009 00:00:00 GMT). A null value specified for the start time or the end time will represent infinity for the start or the end time, respectively, for example, "null, 1230768000000". (默认值为 None) | String |
renderer | The output FeatureSet symbology can be set using a string or dictionary representation of either a JSON renderer or a JSON definition object. Learn more about JSON renderers and JSON definition objects. (默认值为 None) | String |
is_renderer | Specifies the type of the value used with the renderer argument. Set to True if the value is a renderer object; set to False if the value is a definition. (默认值为 None) | Boolean |
geojson_geometry_type | The geometry type of the GeoJSON file that will be loaded. A single GeoJSON file may contain multiple types of geometry records. Only the records of the specified geometry type will be loaded. By default, this is the geometry type of the first record. This option is only supported if the table_path value is GeoJSON.
Only the listed GeoJSON geometry types are supported. (默认值为 None) | String |
属性
| 属性 | 说明 | 数据类型 |
| JSON (只读) | 返回一个字符串形式的几何 Esri JSON 制图表达。 提示：通过 json 模块的 loads 函数，返回的字符串可转换至字典。 | String |
| GeoJSON (只读) | 返回一个字符串形式的几何 GeoJSON 制图表达。 提示：通过 json 模块的 loads 函数，返回的字符串可转换至字典。 | String |
方法概述
| 方法 | 说明 |
| load ({table_path}, {where_clause}, {time_filter}, {renderer}, {is_renderer}, {geojson_geometry_type}) | 将表加载至 FeatureSet 对象。 |
| save (table_path) | 导出到表。 |
方法
load ({table_path}, {where_clause}, {time_filter}, {renderer}, {is_renderer}, {geojson_geometry_type})| 参数 | 说明 | 数据类型 |
table_path | The features to load into the FeatureSet object. The input can be a catalog path to a feature class, a URL to a hosted feature layer, a JSON with the syntax {"url":"<url>", "serviceToken":"<ServiceToken>"} to load data from external sources that require an access token, an Esri (featureSet) JSON string, or a GeoJSON string. Esri JSON and GeoJSON are standards for encoding feature (geometry and attribute) data as a .json file. | String |
where_clause | An SQL expression used to select a subset of records. For more information about SQL syntax, see SQL reference for query expressions used in ArcGIS. (默认值为 None) | String |
time_filter | The time instant or the time extent to query. The time filter can only be applied to hosted feature layers, and the layer must be time enabled. Format a time instant as a string, for example, "1199145600000" (1 Jan 2008 00:00:00 GMT). Format a time extent as a comma-delimited string, for example, "1199145600000, 1230768000000" (1 Jan 2008 00:00:00 GMT to 1 Jan 2009 00:00:00 GMT). A null value specified for the start time or the end time will represent infinity for the start or the end time, respectively, for example, "null, 1230768000000". (默认值为 None) | String |
renderer | The output FeatureSet symbology can be set using a string or dictionary representation of either a JSON renderer or a JSON definition object. Learn more about JSON renderers and JSON definition objects. (默认值为 None) | String |
is_renderer | Specifies the type of the value used with the renderer argument. Set to True if the value is a renderer object; set to False if the value is a definition. (默认值为 None) | Boolean |
geojson_geometry_type | The geometry type of the GeoJSON file that will be loaded. A single GeoJSON file may contain multiple types of geometry records. Only the records of the specified geometry type will be loaded. By default, this is the geometry type of the first record. This option is only supported if the table_path value is GeoJSON.
Only the listed GeoJSON geometry types are supported. (默认值为 None) | String |
save (table_path)
| 参数 | 说明 | 数据类型 |
table_path | 要创建的输出表。 | String |
代码示例
将数据加载到要素类并插入 FeatureSet 对象中。
import arcpy
arcpy.env.overwriteOutput = True
arcpy.ImportToolbox("http://flame7/arcgis/services;BufferByVal",
"servertools")
# List of coordinates
coordinates = [[-117.196717216, 34.046944853],
[-117.186226483, 34.046498438],
[-117.179530271, 34.038016569],
[-117.187454122, 34.039132605],
[-117.177744614, 34.056765964],
[-117.156205131, 34.064466609],
[-117.145491191, 34.068261129],
[-117.170825195, 34.073618099],
[-117.186784501, 34.068149525],
[-117.158325598, 34.03489167]]
# Create an in_memory feature class to initially contain the coordinate pairs
feature_class = arcpy.CreateFeatureclass_management(
"in_memory", "tempfc", "POINT")[0]
# Open an insert cursor
with arcpy.da.InsertCursor(feature_class, ["SHAPE@XY"]) as cursor:
# Iterate through list of coordinates and add to cursor
for (x, y) in coordinates:
cursor.insertRow([(x, y)])
# Create a FeatureSet object and load in_memory feature class
feature_set = arcpy.FeatureSet(feature_class)
results = arcpy.BufferPoints_servertools(feature_set)将 ArcGIS Living Atlas of the World 中的数据子集加载到 FeatureSet 对象中并设置符号系统。
import arcpy
# Set data
in_data = "https://services.arcgis.com/P3ePLMYs2RVChkJx/arcgis/rest/services/USA_States_Generalized/FeatureServer/0"
query = "STATE_NAME = 'California'"
renderer = '''{
"renderer": {
"type": "simple",
"symbol": {
"type": "esriSFS",
"style": "esriSFSSolid",
"color": [
255,
0,
0,
255
],
"outline": {
"type": "esriSLS",
"style": "esriSLSSolid",
"color": [
110,
110,
110,
255
],
"width": 2
}
},
"label": "",
"description": "",
"rotationType": "geographic",
"rotationExpression": ""
}
}'''
# Create FeatureSet with query and renderer
feature_set = arcpy.FeatureSet(in_data, query, renderer=renderer, is_renderer=True)根据 Esri JSON 字符串创建 FeatureSet 对象。
import arcpy
# Set data
esri_json = '''{
"objectIdFieldName": "objectid",
"globalIdFieldName": "globalid",
"geometryType": "esriGeometryPoint",
"spatialReference": {
"wkid": 102100,
"latestWkid": 3857
},
"fields": [
{
"name": "objectid",
"alias": "OBJECTID",
"type": "esriFieldTypeOID"
},
{
"name": "requestid",
"alias": "Service Request ID",
"type": "esriFieldTypeString",
"length": 25
},
{
"name": "requesttype",
"alias": "Problem",
"type": "esriFieldTypeString",
"length": 100
},
{
"name": "comments",
"alias": "Comments",
"type": "esriFieldTypeString",
"length": 255
}
],
"features": [
{
"geometry": {
"x": -9809161.170230601,
"y": 5123045.5266209831
},
"attributes": {
"objectid": 246362,
"requestid": "1",
"requesttype": "Sidewalk Damage",
"comments": "Pothole"
}
},
{
"geometry": {
"x": -9074857.9234435894,
"y": 4982391.2604217697
},
"attributes": {
"objectid": 246382,
"requestid": "2",
"requesttype": "Pothole",
"comments": ""
}
}
]
}'''
# Create FeatureSet from Esri JSON
feature_set = arcpy.FeatureSet(data_json)根据 GeoJSON 字符串创建 FeatureSet 对象。
import arcpy
geo_json = '''{
"crs": {
"properties": {
"name": "EPSG: 3857"
},
"type": "name"
},
"features": [
{
"geometry": {
"coordinates": [
-9809161.170230601,
5123045.526620984
],
"type": "Point"
},
"id": 246362,
"properties": {
"comments": "Pothole",
"objectid": 246362,
"requestid": "1",
"requesttype": "Sidewalk Damage"
},
"type": "Feature"
},
{
"geometry": {
"coordinates": [
-9074857.923443586,
4982391.260421775
],
"type": "Point"
},
"id": 246382,
"properties": {
"comments": "",
"objectid": 246382,
"requestid": "2",
"requesttype": "Pothole"
},
"type": "Feature"
}
],
"type": "FeatureCollection"
}'''
# Create FeatureSet from Geo JSON
feature_set = arcpy.FeatureSet(geo_json, geojson_geometry_type="POINT")使用 time_filter 参数从支持时间的托管要素图层创建一个 FeatureSet 对象。
import arcpy
url = {"url": "https://services.arcgis.com/O9GvsOYzrcFwdwqx/arcgis/rest/services/MyTimeEnabledLayer/FeatureServer/0"}
filter = "Country = 'United States'"
in_start, in_end = 1672473600000, 1718434800000
time_filter = f"{in_start}, {in_end}"
# Create FeatureSet using a time filter
feature_set = arcpy.FeatureSet(table_path=url, time_filter=time_filter)