使用Python将元素附加到JSON dict（geojson）

Question

我想通过Python向我的geojson添加样式。 当前的要素当前没有任何样式元素。 我想附加样式然后填充。 但是，当我这样做时，什么都没有添加到文件中。 和以前一样

import json

with open('test.json') as f:
    data = json.load(f)

for feature in data['features']:
    feature.append("style")
    feature["style"].append({"fill":color})

样例GeoJson

{
"type": "FeatureCollection",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },

"features": [
{ "type": "Feature", "properties": { "STATEFP": "17", "COUNTYFP": "019", "TRACTCE": "005401", "BLKGRPCE": "2", "GEOID": "170190054012", "NAMELSAD": "Block Group 2", "MTFCC": "G5030", "FUNCSTAT": "S", "ALAND": 574246.000000, "AWATER": 4116.000000, "INTPTLAT": "+40.1238204", "INTPTLON": "-088.2038105", "GISJOIN": "G17001900054012", "STUSPS": "IL", "SHAPE_AREA": 578361.706954, "SHAPE_LEN": 3489.996273, "census_block_income_YEAR": "2009-2013", "census_block_income_STATE": "Illinois", "census_block_income_STATEA": 17, "census_block_income_COUNTY": "Champaign County"}}]}

我试图使最终结果是：

    {
"type": "FeatureCollection",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },

"features": [
{ "type": "Feature", "properties": { "STATEFP": "17", "COUNTYFP": "019", "TRACTCE": "005401", "BLKGRPCE": "2", "GEOID": "170190054012", "NAMELSAD": "Block Group 2", "MTFCC": "G5030", "FUNCSTAT": "S", "ALAND": 574246.000000, "AWATER": 4116.000000, "INTPTLAT": "+40.1238204", "INTPTLON": "-088.2038105", "GISJOIN": "G17001900054012", "STUSPS": "IL", "SHAPE_AREA": 578361.706954, "SHAPE_LEN": 3489.996273, "census_block_income_YEAR": "2009-2013", "census_block_income_STATE": "Illinois", "census_block_income_STATEA": 17, "census_block_income_COUNTY": "Champaign County"},"style"{fill:"red"}}]}

Answer 1

您在这里使用词典列表，字典没有方法append ，您可以在此处创建新键：

for feature in data['features']:
    feature["style"] = {"fill":color}

似乎您需要使用JSON重写文件：

with open('test.json', 'w') as f:
    json.dump(data, f)

Answer 2

当您键入

for feature in data['features']:

每个feature都将是data['features']列表中的一项。 每个项目都有一个字典，因此您在调用错误的方法（ append是列表的方法）。

你可以写

for feature in data['features']:
    feature.update({"style": {"fill": "red"}})

最后，如果要更改用于更改初始json结构的文件，请确保将现在更新的数据结构写回到文件中：

with open('output2.json', 'w') as f:
    json.dump(data, f)

Answer 3

词典中没有append方法。 一个应该使用update 。

import pprint as pp
for feature in data['features']:
    feature.update({'style':{'fill': 'red'}})

pp.pprint(data)

输出：

{'crs': {'properties': {'name': 'urn:ogc:def:crs:OGC:1.3:CRS84'},
         'type': 'name'},
 'features': [{'properties': {'ALAND': 574246.0,
                              'AWATER': 4116.0,
                              'BLKGRPCE': '2',
                              'COUNTYFP': '019',
                              'FUNCSTAT': 'S',
                              'GEOID': '170190054012',
                              'GISJOIN': 'G17001900054012',
                              'INTPTLAT': '+40.1238204',
                              'INTPTLON': '-088.2038105',
                              'MTFCC': 'G5030',
                              'NAMELSAD': 'Block Group 2',
                              'SHAPE_AREA': 578361.706954,
                              'SHAPE_LEN': 3489.996273,
                              'STATEFP': '17',
                              'STUSPS': 'IL',
                              'TRACTCE': '005401',
                              'census_block_income_COUNTY': 'Champaign County',
                              'census_block_income_STATE': 'Illinois',
                              'census_block_income_STATEA': 17,
                              'census_block_income_YEAR': '2009-2013'},
               'style': {'fill': 'red'},
               'type': 'Feature'}],
 'type': 'FeatureCollection'}

Answer 4

您永远不会将所做的更改写回到文件中。 在代码末尾添加以下内容：

with open('test.json','w') as f:
    json.dump(data, f)