如何用Python绘制JS地图

Folium是建立在Python生态系统的数据整理（Datawrangling）能力和Leaflet.js库的映射能力之上的开源库。用Python处理数据，然后用Folium将它在Leaflet地图上进行可视化。概念Folium能够将通过Python处理后的数据轻松地在交互式的Leaflet地图上进行可视化展示。它不单单可以在地图上展示数据的分布图，还可以使用Vincent/Vega在地图上加以标记。这个开源库中有许多来自OpenStreetMap、MapQuestOpen、MapQuestOpenAerial、Mapbox和Stamen的内建地图元件，而且支持使用Mapbox或Cloudmade的API密钥来定制个性化的地图元件。Folium支持GeoJSON和TopoJSON两种文件格式的叠加，也可以将数据连接到这两种文件格式的叠加层，最后可使用color-brewer配色方案创建分布图。安装安装folium包开始创建地图创建底图，传入起始坐标到Folium地图中：importfoliummap_osm=folium.Map(location=[45.5236,-122.6750])#输入坐标map_osm.create_map(path='osm.html')Folium默认使用OpenStreetMap元件，但是StamenTerrain,StamenToner,MapboxBright和MapboxControl空间元件是内置的：#输入位置，tiles，缩放比例stamen=folium.Map(location=[45.5236,-122.6750],tiles='StamenToner',zoom_start=13)stamen.create_map(path='stamen_toner.html')#保存图片Folium也支持Cloudmade和Mapbox的个性化定制地图元件，只需简单地传入API_key：custom=folium.Map(location=[45.5236,-122.6750],tiles='Mapbox',API_key='wrobstory.map-12345678')最后，Folium支持传入任何与Leaflet.js兼容的个性化地图元件：tileset=r'http://{s}.tiles.yourtiles.com/{z}/{x}/{y}.png'map=folium.Map(location=[45.372,-121.6972],zoom_start=12,tiles=tileset,attr='MyDataAttribution')地图标记Folium支持多种标记类型的绘制，下面从一个简单的Leaflet类型的位置标记弹出文本开始：map_1=folium.Map(location=[45.372,-121.6972],zoom_start=12,tiles='StamenTerrain')map_1.simple_marker([45.3288,-121.6625],popup='Mt.HoodMeadows')#文字标记map_1.simple_marker([45.3311,-121.7113],popup='TimberlineLodge')map_1.create_map(path='mthood.html')Folium支持多种颜色和标记图标类型：map_1=folium.Map(location=[45.372,-121.6972],zoom_start=12,tiles='StamenTerrain')map_1.simple_marker([45.3288,-121.6625],popup='Mt.HoodMeadows',marker_icon='cloud')#标记图标类型为云map_1.simple_marker([45.3311,-121.7113],popup='TimberlineLodge',marker_color='green')#标记颜色为绿色map_1.simple_marker([45.3300,-121.6823],popup='SomeOtherLocation',marker_color='red',marker_icon='info-sign')#标记颜色为红色，标记图标为“info-sign”)map_1.create_map(path='iconTest.html')Folium也支持使用个性化的尺寸和颜色进行圆形标记：map_2=folium.Map(location=[45.5236,-122.6750],tiles='StamenToner',zoom_start=13)map_2.simple_marker(location=[45.5244,-122.6699],popup='TheWaterfront')简单树叶类型标记map_2.circle_marker(location=[45.5215,-122.6261],radius=500,popup='LaurelhurstPark',line_color='#3186cc',fill_color='#3186cc')#圆形标记map_2.create_map(path='portland.html')Folium有一个简便的功能可以使经/纬度悬浮于地图上：map_3=folium.Map(location=[46.1991,-122.1889],tiles='StamenTerrain',zoom_start=13)map_3.lat_lng_popover()map_3.create_map(path='sthelens.html')Click-for-marker功能允许标记动态放置：map_4=folium.Map(location=[46.8527,-121.7649],tiles='StamenTerrain',zoom_start=13)map_4.simple_marker(location=[46.8354,-121.7325],popup='CampMuir')map_4.click_for_marker(popup='Waypoint')map_4.create_map(path='mtrainier.html')Folium也支持来自Leaflet-DVF的Polygon（多边形）标记集：map_5=folium.Map(location=[45.5236,-122.6750],zoom_start=13)map_5.polygon_marker(location=[45.5012,-122.6655],popup='RossIslandBridge',fill_color='#132b5e',num_sides=3,radius=10)#三边形标记map_5.polygon_marker(location=[45.5132,-122.6708],popup='HawthorneBridge',fill_color='#45647d',num_sides=4,radius=10)#四边形标记map_5.polygon_marker(location=[45.5275,-122.6692],popup='SteelBridge',fill_color='#769d96',num_sides=6,radius=10)#四边形标记map_5.polygon_marker(location=[45.5318,-122.6745],popup='BroadwayBridge',fill_color='#769d96',num_sides=8,radius=10)#八边形标记map_5.create_map(path='bridges.html')Vincent/Vega标记Folium能够使用vincent进行任何类型标记，并悬浮在地图上。buoy_map=folium.Map(location=[46.3014,-123.7390],zoom_start=7,tiles='StamenTerrain')buoy_map.polygon_marker(location=[47.3489,-124.708],fill_color='#43d9de',radius=12,popup=(vis1,'vis1.json'))buoy_map.polygon_marker(location=[44.639,-124.5339],fill_color='#43d9de',radius=12,popup=(vis2,'vis2.json'))buoy_map.polygon_marker(location=[46.216,-124.1280],fill_color='#43d9de',radius=12,popup=(vis3,'vis3.json'))GeoJSON/TopoJSON层叠加GeoJSON和TopoJSON层都可以导入到地图，不同的层可以在同一张地图上可视化出来：geo_path=r'data/antarctic_ice_edge.json'topo_path=r'data/antarctic_ice_shelf_topo.json'ice_map=folium.Map(location=[-59.1759,-11.6016],tiles='MapboxBright',zoom_start=2)ice_map.geo_json(geo_path=geo_path)#导入geoJson层ice_map.geo_json(geo_path=topo_path,topojson='objects.antarctic_ice_shelf')#导入Toposon层ice_map.create_map(path='ice_map.html')分布图Folium允许PandasDataFrames/Series类型和Geo/TopoJSON类型之间数据转换。ColorBrewer颜色方案也是内建在这个库，可以直接导入快速可视化不同的组合：importfoliumimportpandasaspdstate_geo=r'data/us-states.json'#地理位置文件state_unemployment=r'data/US_Unemployment_Oct2012.csv'#美国失业率文件state_data=pd.read_csv(state_unemployment)#LetFoliumdeterminethescalemap=folium.Map(location=[48,-102],zoom_start=3)map.geo_json(geo_path=state_geo,data=state_data,columns=['State','Unemployment'],key_on='feature.id',fill_color='YlGn',fill_opacity=0.7,line_opacity=0.2,legend_name='UnemploymentRate(%)')map.create_map(path='us_states.html')基于D3阈值尺度，Folium在右上方创建图例，通过分位数创建最佳猜测值，导入设定的阈值很简单：map.geo_json(geo_path=state_geo,data=state_data,columns=['State','Unemployment'],threshold_scale=[5,6,7,8,9,10],key_on='feature.id',fill_color='BuPu',fill_opacity=0.7,line_opacity=0.5,legend_name='UnemploymentRate(%)',reset=True)map.create_map(path='us_states.html')