Python 请求从 GeoJSON 文件获取高度

Question

我想从 GeoJSON 文件中获取线段（线串）的高程。

我正在使用这个 API：

• 文档： https://api3.geo.admin.ch/services/sdiservices.html#profile
• 请求 URL: https://api3.geo.admin.ch/rest/services/profile.csv

我的问题是我无法摆脱一个错误，说传递的参数“geom”不是 GeoJSON 类型。

我的 geojson 文件：

{
"type": "FeatureCollection",
"name": "test",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
"features": [
{ "type": "Feature", "properties": { "Name": null, "description": "", "altitudeMode": "clampToGround", "tessellate": 1, "type": "linepolygon" }, "geometry": { "type": "LineString", "coordinates": [ [ 7.349510580151255, 45.998132989830559 ], [ 7.346422156898689, 46.039529058312063 ], [ 7.287112064012824, 46.093617348068292 ], [ 7.236173542687846, 46.127135334945002 ] ] } }
]
}

我的代码：

import requests
import json

api_url = "https://api3.geo.admin.ch/rest/services/profile.csv"
file_path = "geojson.GEOJSON"

with open(file_path) as f:
    geojson = json.load(f)
    r = requests.get(api_url, params=dict(geom=geojson))

print(r.json())

Output：

{'error': {'code': 400, 'message': 'Invalid geom parameter, must be a GEOJSON'}, 'success': False}

编辑：解决方案

import requests
import json

api_url = "https://api3.geo.admin.ch/rest/services/profile.csv"
file_path = "geojson.GEOJSON"

with open(file_path) as f:
    geojson, = json.load(f)['features']
    geom = json.dumps(geojson['geometry'])
    r = requests.get(api_url, params=dict(geom=geom))

print(r.json())

注意：仍然存在问题，但参数“sr”： 请求引发“JSONDecodeError：额外数据”

Answer 1

查看文档中的示例。 API 想要一个单一的几何图形，比如{"type": "LineString", "coordinates": [[1,2], [3,4]]} ; 你给它一个完整的 FeatureCollection。