geopandas.GeoDataFrame.from_postgis

classmethod GeoDataFrame.from_postgis(sql, con, geom_col='geom', crs=None, index_col=None, coerce_float=True, parse_dates=None, params=None, chunksize=None)

Alternate constructor to create a GeoDataFrame from a sql query containing a geometry column in WKB representation.

Parameters

sqlstring

consqlalchemy.engine.Connection or sqlalchemy.engine.Engine

geom_colstring, default ‘geom’

column name to convert to shapely geometries

crsoptional

Coordinate reference system to use for the returned GeoDataFrame

index_colstring or list of strings, optional, default: None

Column(s) to set as index(MultiIndex)

coerce_floatboolean, default True

Attempt to convert values of non-string, non-numeric objects (like decimal.Decimal) to floating point, useful for SQL result sets

parse_dateslist or dict, default None

• List of column names to parse as dates.

• Dict of {column_name: format string} where format string is strftime compatible in case of parsing string times, or is one of (D, s, ns, ms, us) in case of parsing integer timestamps.

• Dict of {column_name: arg dict}, where the arg dict corresponds to the keyword arguments of pandas.to_datetime(). Especially useful with databases without native Datetime support, such as SQLite.

paramslist, tuple or dict, optional, default None

List of parameters to pass to execute method.

chunksizeint, default None

If specified, return an iterator where chunksize is the number of rows to include in each chunk.

See also

geopandas.read_postgis

read PostGIS database to GeoDataFrame

Examples

PostGIS

>>> from sqlalchemy import create_engine  
>>> db_connection_url = "postgresql://myusername:mypassword@myhost:5432/mydb"
>>> con = create_engine(db_connection_url)  
>>> sql = "SELECT geom, highway FROM roads"
>>> df = geopandas.GeoDataFrame.from_postgis(sql, con)  

SpatiaLite

>>> sql = "SELECT ST_Binary(geom) AS geom, highway FROM roads"
>>> df = geopandas.GeoDataFrame.from_postgis(sql, con)  

The recommended method of reading from PostGIS is geopandas.read_postgis():

>>> df = geopandas.read_postgis(sql, con)  

geopandas.GeoDataFrame.from_features geopandas.GeoDataFrame.to_file