"""Polygons and Linear Rings"""
import numpy as np
import pytest
from shapely import LinearRing, LineString, Point, Polygon
from shapely.coords import CoordinateSequence
from shapely.errors import TopologicalError
from shapely.wkb import loads as load_wkb
def test_empty_linearring_coords():
assert LinearRing().coords[:] == []
def test_linearring_from_coordinate_sequence():
expected_coords = [(0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (0.0, 0.0)]
ring = LinearRing([(0.0, 0.0), (0.0, 1.0), (1.0, 1.0)])
assert ring.coords[:] == expected_coords
ring = LinearRing([(0.0, 0.0), (0.0, 1.0), (1.0, 1.0)])
assert ring.coords[:] == expected_coords
def test_linearring_from_points():
# From Points
expected_coords = [(0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (0.0, 0.0)]
ring = LinearRing([Point(0.0, 0.0), Point(0.0, 1.0), Point(1.0, 1.0)])
assert ring.coords[:] == expected_coords
def test_linearring_from_closed_linestring():
coords = [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 0.0)]
line = LineString(coords)
ring = LinearRing(line)
assert len(ring.coords) == 4
assert ring.coords[:] == coords
assert ring.geom_type == "LinearRing"
def test_linearring_from_unclosed_linestring():
coords = [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 0.0)]
line = LineString(coords[:-1]) # Pass in unclosed line
ring = LinearRing(line)
assert len(ring.coords) == 4
assert ring.coords[:] == coords
assert ring.geom_type == "LinearRing"
def test_linearring_from_invalid():
coords = [(0.0, 0.0), (0.0, 0.0), (0.0, 0.0)]
line = LineString(coords)
assert not line.is_valid
with pytest.raises(TopologicalError):
LinearRing(line)
def test_linearring_from_too_short_linestring():
# Creation of LinearRing request at least 3 coordinates (unclosed) or
# 4 coordinates (closed)
coords = [(0.0, 0.0), (1.0, 1.0)]
line = LineString(coords)
with pytest.raises(ValueError, match="requires at least 4 coordinates"):
LinearRing(line)
def test_linearring_from_linearring():
coords = [(0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (0.0, 0.0)]
ring = LinearRing(coords)
assert ring.coords[:] == coords
def test_linearring_from_generator():
coords = [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 0.0)]
gen = (coord for coord in coords)
ring = LinearRing(gen)
assert ring.coords[:] == coords
def test_linearring_from_empty():
ring = LinearRing()
assert ring.is_empty
assert isinstance(ring.coords, CoordinateSequence)
assert ring.coords[:] == []
ring = LinearRing([])
assert ring.is_empty
assert isinstance(ring.coords, CoordinateSequence)
assert ring.coords[:] == []
def test_linearring_from_numpy():
# Construct from a numpy array
coords = [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 0.0)]
ring = LinearRing(np.array(coords))
assert ring.coords[:] == [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 0.0)]
def test_numpy_linearring_coords():
from numpy.testing import assert_array_equal
ring = LinearRing([(0.0, 0.0), (0.0, 1.0), (1.0, 1.0)])
ra = np.asarray(ring.coords)
expected = np.asarray([(0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (0.0, 0.0)])
assert_array_equal(ra, expected)
def test_numpy_empty_linearring_coords():
ring = LinearRing()
assert np.asarray(ring.coords).shape == (0, 2)
def test_numpy_object_array():
geom = Polygon([(0.0, 0.0), (0.0, 1.0), (1.0, 1.0)])
ar = np.empty(1, object)
ar[:] = [geom]
assert ar[0] == geom
def test_polygon_from_coordinate_sequence():
coords = [(0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (0.0, 0.0)]
# Construct a polygon, exterior ring only
polygon = Polygon([(0.0, 0.0), (0.0, 1.0), (1.0, 1.0)])
assert polygon.exterior.coords[:] == coords
assert len(polygon.interiors) == 0
polygon = Polygon([(0.0, 0.0), (0.0, 1.0), (1.0, 1.0)])
assert polygon.exterior.coords[:] == coords
assert len(polygon.interiors) == 0
def test_polygon_from_coordinate_sequence_with_holes():
coords = [(0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (0.0, 0.0)]
# Interior rings (holes)
polygon = Polygon(coords, [[(0.25, 0.25), (0.25, 0.5), (0.5, 0.5), (0.5, 0.25)]])
assert polygon.exterior.coords[:] == coords
assert len(polygon.interiors) == 1
assert len(polygon.interiors[0].coords) == 5
# Multiple interior rings with different length
coords = [(0, 0), (0, 10), (10, 10), (10, 0), (0, 0)]
holes = [
[(1, 1), (2, 1), (2, 2), (1, 2), (1, 1)],
[(3, 3), (3, 4), (4, 5), (5, 4), (5, 3), (3, 3)],
]
polygon = Polygon(coords, holes)
assert polygon.exterior.coords[:] == coords
assert len(polygon.interiors) == 2
assert len(polygon.interiors[0].coords) == 5
assert len(polygon.interiors[1].coords) == 6
def test_polygon_from_linearring():
coords = [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 0.0)]
ring = LinearRing(coords)
polygon = Polygon(ring)
assert polygon.exterior.coords[:] == coords
assert len(polygon.interiors) == 0
# from shell and holes linearrings
shell = LinearRing([(0.0, 0.0), (70.0, 120.0), (140.0, 0.0), (0.0, 0.0)])
holes = [
LinearRing([(60.0, 80.0), (80.0, 80.0), (70.0, 60.0), (60.0, 80.0)]),
LinearRing([(30.0, 10.0), (50.0, 10.0), (40.0, 30.0), (30.0, 10.0)]),
LinearRing([(90.0, 10), (110.0, 10.0), (100.0, 30.0), (90.0, 10.0)]),
]
polygon = Polygon(shell, holes)
assert polygon.exterior.coords[:] == shell.coords[:]
assert len(polygon.interiors) == 3
for i in range(3):
assert polygon.interiors[i].coords[:] == holes[i].coords[:]
def test_polygon_from_linestring():
coords = [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 0.0)]
line = LineString(coords)
polygon = Polygon(line)
assert polygon.exterior.coords[:] == coords
# from unclosed linestring
line = LineString(coords[:-1])
polygon = Polygon(line)
assert polygon.exterior.coords[:] == coords
def test_polygon_from_points():
polygon = Polygon([Point(0.0, 0.0), Point(0.0, 1.0), Point(1.0, 1.0)])
expected_coords = [(0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (0.0, 0.0)]
assert polygon.exterior.coords[:] == expected_coords
def test_polygon_from_polygon():
coords = [(0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (1.0, 0.0)]
polygon = Polygon(coords, [[(0.25, 0.25), (0.25, 0.5), (0.5, 0.5), (0.5, 0.25)]])
# Test from another Polygon
copy = Polygon(polygon)
assert len(copy.exterior.coords) == 5
assert len(copy.interiors) == 1
assert len(copy.interiors[0].coords) == 5
def test_polygon_from_invalid():
# Error handling
with pytest.raises(ValueError):
# A LinearRing must have at least 3 coordinate tuples
Polygon([[1, 2], [2, 3]])
def test_polygon_from_empty():
polygon = Polygon()
assert polygon.is_empty
assert polygon.exterior.coords[:] == []
polygon = Polygon([])
assert polygon.is_empty
assert polygon.exterior.coords[:] == []
def test_polygon_from_numpy():
a = np.array(((0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (1.0, 0.0), (0.0, 0.0)))
polygon = Polygon(a)
assert len(polygon.exterior.coords) == 5
assert polygon.exterior.coords[:] == [
(0.0, 0.0),
(0.0, 1.0),
(1.0, 1.0),
(1.0, 0.0),
(0.0, 0.0),
]
assert len(polygon.interiors) == 0
def test_polygon_from_generator():
coords = [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 0.0)]
gen = (coord for coord in coords)
polygon = Polygon(gen)
assert polygon.exterior.coords[:] == coords
class TestPolygon:
def test_linearring(self):
# Initialization
# Linear rings won't usually be created by users, but by polygons
coords = ((0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (1.0, 0.0))
ring = LinearRing(coords)
assert len(ring.coords) == 5
assert ring.coords[0] == ring.coords[4]
assert ring.coords[0] == ring.coords[-1]
assert ring.is_ring is True
def test_polygon(self):
coords = ((0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (1.0, 0.0))
# Construct a polygon, exterior ring only
polygon = Polygon(coords)
assert len(polygon.exterior.coords) == 5
# Ring Access
assert isinstance(polygon.exterior, LinearRing)
ring = polygon.exterior
assert len(ring.coords) == 5
assert ring.coords[0] == ring.coords[4]
assert ring.coords[0] == (0.0, 0.0)
assert ring.is_ring is True
assert len(polygon.interiors) == 0
# Create a new polygon from WKB
data = polygon.wkb
polygon = None
ring = None
polygon = load_wkb(data)
ring = polygon.exterior
assert len(ring.coords) == 5
assert ring.coords[0] == ring.coords[4]
assert ring.coords[0] == (0.0, 0.0)
assert ring.is_ring is True
polygon = None
# Interior rings (holes)
polygon = Polygon(
coords, [((0.25, 0.25), (0.25, 0.5), (0.5, 0.5), (0.5, 0.25))]
)
assert len(polygon.exterior.coords) == 5
assert len(polygon.interiors[0].coords) == 5
with pytest.raises(IndexError): # index out of range
polygon.interiors[1]
# Coordinate getter raises exceptions
with pytest.raises(NotImplementedError):
polygon.coords
# Geo interface
assert polygon.__geo_interface__ == {
"type": "Polygon",
"coordinates": (
((0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (1.0, 0.0), (0.0, 0.0)),
((0.25, 0.25), (0.25, 0.5), (0.5, 0.5), (0.5, 0.25), (0.25, 0.25)),
),
}
def test_linearring_empty(self):
# Test Non-operability of Null rings
r_null = LinearRing()
assert r_null.wkt == "LINEARRING EMPTY"
assert r_null.length == 0.0
def test_dimensions(self):
# Background: see http://trac.gispython.org/lab/ticket/168
# http://lists.gispython.org/pipermail/community/2008-August/001859.html
coords = ((0.0, 0.0, 0.0), (0.0, 1.0, 0.0), (1.0, 1.0, 0.0), (1.0, 0.0, 0.0))
polygon = Polygon(coords)
assert polygon._ndim == 3
gi = polygon.__geo_interface__
assert gi["coordinates"] == (
(
(0.0, 0.0, 0.0),
(0.0, 1.0, 0.0),
(1.0, 1.0, 0.0),
(1.0, 0.0, 0.0),
(0.0, 0.0, 0.0),
),
)
e = polygon.exterior
assert e._ndim == 3
gi = e.__geo_interface__
assert gi["coordinates"] == (
(0.0, 0.0, 0.0),
(0.0, 1.0, 0.0),
(1.0, 1.0, 0.0),
(1.0, 0.0, 0.0),
(0.0, 0.0, 0.0),
)
def test_attribute_chains(self):
# Attribute Chaining
# See also ticket #151.
p = Polygon([(0.0, 0.0), (0.0, 1.0), (-1.0, 1.0), (-1.0, 0.0)])
assert list(p.boundary.coords) == [
(0.0, 0.0),
(0.0, 1.0),
(-1.0, 1.0),
(-1.0, 0.0),
(0.0, 0.0),
]
ec = list(Point(0.0, 0.0).buffer(1.0, quad_segs=1).exterior.coords)
assert isinstance(ec, list) # TODO: this is a poor test
# Test chained access to interiors
p = Polygon(
[(0.0, 0.0), (0.0, 1.0), (-1.0, 1.0), (-1.0, 0.0)],
[[(-0.25, 0.25), (-0.25, 0.75), (-0.75, 0.75), (-0.75, 0.25)]],
)
assert p.area == 0.75
"""Not so much testing the exact values here, which are the
responsibility of the geometry engine (GEOS), but that we can get
chain functions and properties using anonymous references.
"""
assert list(p.interiors[0].coords) == [
(-0.25, 0.25),
(-0.25, 0.75),
(-0.75, 0.75),
(-0.75, 0.25),
(-0.25, 0.25),
]
xy = next(iter(p.interiors[0].buffer(1).exterior.coords))
assert len(xy) == 2
# Test multiple operators, boundary of a buffer
ec = list(p.buffer(1).boundary.coords)
assert isinstance(ec, list) # TODO: this is a poor test
def test_empty_equality(self):
# Test equals operator, including empty geometries
# see issue #338
point1 = Point(0, 0)
polygon1 = Polygon([(0.0, 0.0), (0.0, 1.0), (-1.0, 1.0), (-1.0, 0.0)])
polygon2 = Polygon([(0.0, 0.0), (0.0, 1.0), (-1.0, 1.0), (-1.0, 0.0)])
polygon_empty1 = Polygon()
polygon_empty2 = Polygon()
assert point1 != polygon1
assert polygon_empty1 == polygon_empty2
assert polygon1 != polygon_empty1
assert polygon1 == polygon2
assert polygon_empty1 is not None
def test_from_bounds(self):
xmin, ymin, xmax, ymax = -180, -90, 180, 90
coords = [(xmin, ymin), (xmin, ymax), (xmax, ymax), (xmax, ymin)]
assert Polygon(coords) == Polygon.from_bounds(xmin, ymin, xmax, ymax)
def test_empty_polygon_exterior(self):
p = Polygon()
assert p.exterior == LinearRing()
def test_linearring_immutable():
ring = LinearRing([(0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (1.0, 0.0)])
with pytest.raises(AttributeError):
ring.coords = [(1.0, 1.0), (2.0, 2.0), (1.0, 2.0)]
with pytest.raises(TypeError):
ring.coords[0] = (1.0, 1.0)
class TestLinearRingGetItem:
def test_index_linearring(self):
shell = LinearRing([(0.0, 0.0), (70.0, 120.0), (140.0, 0.0), (0.0, 0.0)])
holes = [
LinearRing([(60.0, 80.0), (80.0, 80.0), (70.0, 60.0), (60.0, 80.0)]),
LinearRing([(30.0, 10.0), (50.0, 10.0), (40.0, 30.0), (30.0, 10.0)]),
LinearRing([(90.0, 10), (110.0, 10.0), (100.0, 30.0), (90.0, 10.0)]),
]
g = Polygon(shell, holes)
for i in range(-3, 3):
assert g.interiors[i].equals(holes[i])
with pytest.raises(IndexError):
g.interiors[3]
with pytest.raises(IndexError):
g.interiors[-4]
def test_index_linearring_misc(self):
g = Polygon() # empty
with pytest.raises(IndexError):
g.interiors[0]
with pytest.raises(TypeError):
g.interiors[0.0]
def test_slice_linearring(self):
shell = LinearRing([(0.0, 0.0), (70.0, 120.0), (140.0, 0.0), (0.0, 0.0)])
holes = [
LinearRing([(60.0, 80.0), (80.0, 80.0), (70.0, 60.0), (60.0, 80.0)]),
LinearRing([(30.0, 10.0), (50.0, 10.0), (40.0, 30.0), (30.0, 10.0)]),
LinearRing([(90.0, 10), (110.0, 10.0), (100.0, 30.0), (90.0, 10.0)]),
]
g = Polygon(shell, holes)
t = [a.equals(b) for (a, b) in zip(g.interiors[1:], holes[1:])]
assert all(t)
t = [a.equals(b) for (a, b) in zip(g.interiors[:-1], holes[:-1])]
assert all(t)
t = [a.equals(b) for (a, b) in zip(g.interiors[::-1], holes[::-1])]
assert all(t)
t = [a.equals(b) for (a, b) in zip(g.interiors[::2], holes[::2])]
assert all(t)
t = [a.equals(b) for (a, b) in zip(g.interiors[:3], holes[:3])]
assert all(t)
assert g.interiors[3:] == holes[3:] == []