How to create a shapely Polygon from a list of shapely Points?

I want to create a polygon from shapely points.

from shapely import geometry p1 = geometry.Point(0,0) p2 = geometry.Point(1,0) p3 = geometry.Point(1,1) p4 = geometry.Point(0,1) pointList = [p1, p2, p3, p4, p1] poly = geometry.Polygon(pointList) 

gives me an type error TypeError: object of type 'Point' has no len()

How to create a Polygon from shapely Point objects?

5 Answers

If you specifically want to construct your Polygon from the shapely geometry Points, then call their x, y properties in a list comprehension. In other words:

from shapely import geometry poly = geometry.Polygon([[p.x, p.y] for p in pointList]) print(poly.wkt) # prints: 'POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))' 

Note that shapely is clever enough to close the polygon on your behalf, i.e. you don't necessarily have to pass-in the first point again at the end.

A Polygon object requires a nested list of numbers, not a list of Point objects.

polygon = Polygon([[0, 0], [1, 0], [1, 1], [0, 1]]) 

In version 1.7a2 they have fixed this.

The code in question will just work.

Link to CHANGES.txt

The Polygon constructor doesn't expect a list of Point objects but a list of point coordinates.

See

You could just do that instead:

p1 = geometry.Point(0,0) p2 = geometry.Point(1,0) p3 = geometry.Point(1,1) p4 = geometry.Point(0,1) pointList = [p1, p2, p3, p4] poly = geometry.Polygon([i for i in pointList])