如何利用Python将GeoJSON转换为CSV

什么是GeoJSON？

GeoJSON是一种RFC标准化的数据格式，用于编码地理数据结构，如Point、LineString、Polygon、MultiPoint、MultiLineString和MultiPolygon。GeoJSON是基于JavaScript对象符号（JSON）的。

GeoJSON到CSV的例子

假设你有以下的GeoJSON片段。

{ 
    "type": "FeatureCollection",
    "features": [
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [-75.343, 39.984]},
        "properties": { 
          "name": "Location A",
          "category": "Store"
        }
      },
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [-80.24, 40.12]},
        "properties": { 
          "name": "Location B",
          "category": "House"
        }
      },
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [ -77.2, 41.427]},
        "properties": { 
          "name": "Location C",
          "category": "Office"
        }
      }
    ]
  }

你想把它转换为以下CSV格式。

latitude,longitude,altitude,geometry,name,category
39.984,-75.343,,Point,Location A,Store
40.12,-80.24,,Point,Location B,House
41.427,-77.2,,Point,Location C,Office

Python GeoJSON到CSV的转换

在Python中把GeoJSON转换为CSV的代码使用了json 和csv 包的组合。

import json
import csv


geo_filename = 'my_file.json'
csv_filename = 'my_file.csv'


def feature_to_row(feature, header):
    l = []
    for k in header:
        l.append(feature['properties'][k])
    coords = feature['geometry']['coordinates']
    assert(len(coords)==2)
    l.extend(coords)
    return l


with open(geo_filename, 'r') as geo_file:
    with open(csv_filename, 'w', newline='') as csv_file:
        geojson_data = json.load(geo_file)
        features = geojson_data['features']
        
        csv_writer = csv.writer(csv_file)

        is_header = True
        header = []

        for feature in features:
            if is_header:
                is_header = False
                header = list(feature['properties'].keys())
                header.extend(['px','py'])
                csv_writer.writerow(header)
                
            csv_writer.writerow(feature_to_row(feature, feature['properties'].keys()))

你可以复制&粘贴这段代码，并在与你的GeoJSON相同的文件夹中运行它（当然，在重命名输入和输出文件名之后。

或者你可以查看这个优秀的GitHub，以获得一个更 "可编写 "的变体，在命令行中使用。这段代码是受GitHub的启发，但大大简化了。

输入示例。

{ 
    "type": "FeatureCollection",
    "features": [
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [-75.343, 39.984]},
        "properties": { 
          "name": "Location A",
          "category": "Store"
        }
      },
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [-80.24, 40.12]},
        "properties": { 
          "name": "Location B",
          "category": "House"
        }
      },
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [ -77.2, 41.427]},
        "properties": { 
          "name": "Location C",
          "category": "Office"
        }
      }
    ]
  }

输出示例。

QGIS中的GeoJSON到CSV

在QGIS中，如果你有一张像这样的地图（来源）。

你可以在QGIS中直接将GEOJSON转换为CSV，点击Export ，然后Save Feature As ，在第一个下拉菜单中选择逗号分隔值[CSV]选择器。

GeoJSON到CSV在线转换器

您可以使用以下在线转换器轻松地将特定的GeoJSON片段转换为CSV。