including SRID in WKBWriter in Shapely doesn't work

Question

I want to encode coordinates of LineString in WKB with the SRID included

wkbwriter = shapely.geos.WKBWriter(shapely.geos.lgeos, big_endian=False, include_srid=True)

geo = wkbwriter.write_hex(LineString(geometry_obj['coordinates']))

but it is the same exact as

shapely.geometry.shape(geometry_obj).wkb_hex

and does not include the SRID in the encoding, causing issues when trying to store it in postgis with column Geometry('LineString', 3857)

what am I doing wrong?

Guillaume · Answer

I had the same issue.
This is not a big problem. 
Instead of having the SRID code inside you can use this syntax when exporting in postgis:

"ST_GeomFromText('{}',{})".format(geometry,srid)

Hope that helps

Mike T · Answer

The easiest way is to use wkb.dumps, e.g.:
from shapely import wkb, wkb

# example geometry
g = wkt.loads('LINESTRING(2 3, 4 5)')

# without SRID
wkb.dumps(g, hex=True)
# 0102000000020000000000000000000040000000000000084000000000000010400000000000001440

# with SRID=3857
wkb.dumps(g, hex=True, srid=3857)
# 0102000020110F0000020000000000000000000040000000000000084000000000000010400000000000001440

2 Answers