pythonshapefileshapely

How to save Shapely geometry into a file and load it later into a variable

How to save shapely.geometry.polygon.Polygon object into a file (especially to a shapefile) and load it later into the Python environment when it is needed?

from shapely import geometry
q = [(82,32.261),(79.304,32.474),(77.282,30.261),(81.037,28.354)]
polygon = geometry.Polygon(q)

I want to save polygon object to a shapefile (or any other formatted file) and want to load it later when it is needed.

Solution

  • Late to the party. But this is how I like to do it, nice and simple with pickle.

    from shapely import geometry
import pickle

# Make a polygon
q = [(82,32.261),(79.304,32.474),(77.282,30.261),(81.037,28.354)]
polygon = geometry.Polygon(q)

# Check it out
print('My new polygon: \n', polygon)


# Save polygon to disc
with open('./my_polygon', "wb") as poly_file:
    pickle.dump(polygon, poly_file, pickle.HIGHEST_PROTOCOL)

# Load polygon from disc
with open('./my_polygon', "rb") as poly_file:
    loaded_polygon = pickle.load(poly_file)

# Check it out again
print('My loaded polygon: \n', loaded_polygon)

    OUT:

    My new polygon: 
 POLYGON ((82 32.261, 79.304 32.474, 77.282 30.261, 81.03700000000001 28.354, 82 32.261))
My loaded polygon: 
 POLYGON ((82 32.261, 79.304 32.474, 77.282 30.261, 81.03700000000001 28.354, 82 32.261))

    cheers!