Reading and Writing Files¶
Reading Spatial Data¶
geopandas can read almost any vector-based spatial data format including ESRI shapefile, GeoJSON files and more using the command:
geopandas.read_file()
which returns a GeoDataFrame object. (This is possible because geopandas makes use of the great fiona library, which in turn makes use of a massive open-source program called GDAL/OGR designed to facilitate spatial data transformations).
Any arguments passed to read_file()
after the file name will be passed directly to fiona.open
, which does the actual data importation. In general, read_file
is pretty smart and should do what you want without extra arguments, but for more help, type:
import fiona; help(fiona.open)
Among other things, one can explicitly set the driver (shapefile, GeoJSON) with the driver
keyword, or pick a single layer from a multi-layered file with the layer
keyword.
Where supported in fiona
, geopandas can also load resources directly from
a web URL, for example for GeoJSON files from geojson.xyz:
url = "http://d2ad6b4ur7yvpq.cloudfront.net/naturalearth-3.3.0/ne_110m_land.geojson"
df = geopandas.read_file(url)
geopandas can also get data from a PostGIS database using the read_postgis()
command.
Writing Spatial Data¶
GeoDataFrames can be exported to many different standard formats using the GeoDataFrame.to_file()
method. For a full list of supported formats, type import fiona; fiona.supported_drivers
.