Rearranged imports in geos files

6 files changed, 58 insertions, 57 deletions

diff --git a/django/contrib/gis/geos/collections.py b/django/contrib/gis/geos/collections.py
index 0b787f9d53..32176673c1 100644
--- a/django/contrib/gis/geos/collections.py
+++ b/django/contrib/gis/geos/collections.py
@@ -5,7 +5,9 @@
 from ctypes import byref, c_int, c_uint
 
 from django.contrib.gis.geos import prototypes as capi
-from django.contrib.gis.geos.geometry import GEOSGeometry
+from django.contrib.gis.geos.geometry import (
+    GEOSGeometry, ProjectInterpolateMixin,
+)
 from django.contrib.gis.geos.libgeos import get_pointer_arr
 from django.contrib.gis.geos.linestring import LinearRing, LineString
 from django.contrib.gis.geos.point import Point
@@ -99,7 +101,7 @@ class MultiPoint(GeometryCollection):
     _typeid = 4
 
 
-class MultiLineString(GeometryCollection):
+class MultiLineString(ProjectInterpolateMixin, GeometryCollection):
     _allowed = (LineString, LinearRing)
     _typeid = 5
 
diff --git a/django/contrib/gis/geos/geometry.py b/django/contrib/gis/geos/geometry.py
index 42cecc59c8..4cbd561e3c 100644
--- a/django/contrib/gis/geos/geometry.py
+++ b/django/contrib/gis/geos/geometry.py
@@ -14,6 +14,7 @@ from django.contrib.gis.geos.coordseq import GEOSCoordSeq
 from django.contrib.gis.geos.error import GEOSException, GEOSIndexError
 from django.contrib.gis.geos.libgeos import GEOM_PTR
 from django.contrib.gis.geos.mutable_list import ListMixin
+from django.contrib.gis.geos.prepared import PreparedGeometry
 from django.contrib.gis.geos.prototypes.io import (
     ewkb_w, wkb_r, wkb_w, wkt_r, wkt_w,
 )
@@ -27,8 +28,10 @@ class GEOSGeometry(GEOSBase, ListMixin):
     # Raise GEOSIndexError instead of plain IndexError
     # (see ticket #4740 and GEOSIndexError docstring)
     _IndexError = GEOSIndexError
+    _GEOS_CLASSES = None
 
     ptr_type = GEOM_PTR
+    has_cs = False  # Only Point, LineString, LinearRing have coordinate sequences
 
     def __init__(self, geo_input, srid=None):
         """
@@ -92,7 +95,24 @@ class GEOSGeometry(GEOSBase, ListMixin):
             self.srid = srid
 
         # Setting the class type (e.g., Point, Polygon, etc.)
-        self.__class__ = GEOS_CLASSES[self.geom_typeid]
+        if GEOSGeometry._GEOS_CLASSES is None:
+            # Lazy-loaded variable to avoid import conflicts with GEOSGeometry.
+            from .linestring import LineString, LinearRing
+            from .point import Point
+            from .polygon import Polygon
+            from .collections import (
+                GeometryCollection, MultiPoint, MultiLineString, MultiPolygon)
+            GEOSGeometry._GEOS_CLASSES = {
+                0: Point,
+                1: LineString,
+                2: LinearRing,
+                3: Polygon,
+                4: MultiPoint,
+                5: MultiLineString,
+                6: MultiPolygon,
+                7: GeometryCollection,
+            }
+        self.__class__ = GEOSGeometry._GEOS_CLASSES[self.geom_typeid]
 
         # Setting the coordinate sequence for the geometry (will be None on
         # geometries that do not have coordinate sequences)
@@ -185,15 +205,6 @@ class GEOSGeometry(GEOSBase, ListMixin):
         return self.sym_difference(other)
 
     # #### Coordinate Sequence Routines ####
-    @property
-    def has_cs(self):
-        "Returns True if this Geometry has a coordinate sequence, False if not."
-        # Only these geometries are allowed to have coordinate sequences.
-        if isinstance(self, (Point, LineString, LinearRing)):
-            return True
-        else:
-            return False
-
     def _set_cs(self):
         "Sets the coordinate sequence for this Geometry."
         if self.has_cs:
@@ -560,16 +571,6 @@ class GEOSGeometry(GEOSBase, ListMixin):
         "Return the envelope for this geometry (a polygon)."
         return self._topology(capi.geos_envelope(self.ptr))
 
-    def interpolate(self, distance):
-        if not isinstance(self, (LineString, MultiLineString)):
-            raise TypeError('interpolate only works on LineString and MultiLineString geometries')
-        return self._topology(capi.geos_interpolate(self.ptr, distance))
-
-    def interpolate_normalized(self, distance):
-        if not isinstance(self, (LineString, MultiLineString)):
-            raise TypeError('interpolate only works on LineString and MultiLineString geometries')
-        return self._topology(capi.geos_interpolate_normalized(self.ptr, distance))
-
     def intersection(self, other):
         "Returns a Geometry representing the points shared by this Geometry and other."
         return self._topology(capi.geos_intersection(self.ptr, other.ptr))
@@ -579,20 +580,6 @@ class GEOSGeometry(GEOSBase, ListMixin):
         "Computes an interior point of this Geometry."
         return self._topology(capi.geos_pointonsurface(self.ptr))
 
-    def project(self, point):
-        if not isinstance(point, Point):
-            raise TypeError('locate_point argument must be a Point')
-        if not isinstance(self, (LineString, MultiLineString)):
-            raise TypeError('locate_point only works on LineString and MultiLineString geometries')
-        return capi.geos_project(self.ptr, point.ptr)
-
-    def project_normalized(self, point):
-        if not isinstance(point, Point):
-            raise TypeError('locate_point argument must be a Point')
-        if not isinstance(self, (LineString, MultiLineString)):
-            raise TypeError('locate_point only works on LineString and MultiLineString geometries')
-        return capi.geos_project_normalized(self.ptr, point.ptr)
-
     def relate(self, other):
         "Returns the DE-9IM intersection matrix for this Geometry and the other."
         return capi.geos_relate(self.ptr, other.ptr).decode()
@@ -647,6 +634,7 @@ class GEOSGeometry(GEOSBase, ListMixin):
         Returns the extent of this geometry as a 4-tuple, consisting of
         (xmin, ymin, xmax, ymax).
         """
+        from .point import Point
         env = self.envelope
         if isinstance(env, Point):
             xmin, ymin = env.tuple
@@ -668,21 +656,25 @@ class GEOSGeometry(GEOSBase, ListMixin):
         "Clones this Geometry."
         return GEOSGeometry(capi.geom_clone(self.ptr), srid=self.srid)
 
-# Class mapping dictionary.  Has to be at the end to avoid import
-# conflicts with GEOSGeometry.
-from django.contrib.gis.geos.linestring import LineString, LinearRing  # isort:skip
-from django.contrib.gis.geos.point import Point                     # isort:skip
-from django.contrib.gis.geos.polygon import Polygon                 # isort:skip
-from django.contrib.gis.geos.collections import (                   # isort:skip
-    GeometryCollection, MultiPoint, MultiLineString, MultiPolygon)
-from django.contrib.gis.geos.prepared import PreparedGeometry       # isort:skip
-GEOS_CLASSES = {
-    0: Point,
-    1: LineString,
-    2: LinearRing,
-    3: Polygon,
-    4: MultiPoint,
-    5: MultiLineString,
-    6: MultiPolygon,
-    7: GeometryCollection,
-}
+
+class ProjectInterpolateMixin(object):
+    """
+    Used for LineString and MultiLineString.
+    """
+    def interpolate(self, distance):
+        return self._topology(capi.geos_interpolate(self.ptr, distance))
+
+    def interpolate_normalized(self, distance):
+        return self._topology(capi.geos_interpolate_normalized(self.ptr, distance))
+
+    def project(self, point):
+        from .point import Point
+        if not isinstance(point, Point):
+            raise TypeError('locate_point argument must be a Point')
+        return capi.geos_project(self.ptr, point.ptr)
+
+    def project_normalized(self, point):
+        from .point import Point
+        if not isinstance(point, Point):
+            raise TypeError('locate_point argument must be a Point')
+        return capi.geos_project_normalized(self.ptr, point.ptr)
diff --git a/django/contrib/gis/geos/libgeos.py b/django/contrib/gis/geos/libgeos.py
index 1a74819da8..500825a700 100644
--- a/django/contrib/gis/geos/libgeos.py
+++ b/django/contrib/gis/geos/libgeos.py
@@ -135,6 +135,9 @@ lgeos = SimpleLazyObject(load_geos)
 
 
 class GEOSFuncFactory(object):
+    """
+    Lazy loading of GEOS functions.
+    """
     argtypes = None
     restype = None
     errcheck = None
diff --git a/django/contrib/gis/geos/linestring.py b/django/contrib/gis/geos/linestring.py
index 82ae9a2a4e..8e191c4b04 100644
--- a/django/contrib/gis/geos/linestring.py
+++ b/django/contrib/gis/geos/linestring.py
@@ -1,15 +1,18 @@
 from django.contrib.gis.geos import prototypes as capi
 from django.contrib.gis.geos.coordseq import GEOSCoordSeq
 from django.contrib.gis.geos.error import GEOSException
-from django.contrib.gis.geos.geometry import GEOSGeometry
+from django.contrib.gis.geos.geometry import (
+    GEOSGeometry, ProjectInterpolateMixin,
+)
 from django.contrib.gis.geos.point import Point
 from django.contrib.gis.shortcuts import numpy
 from django.utils.six.moves import range
 
 
-class LineString(GEOSGeometry):
+class LineString(ProjectInterpolateMixin, GEOSGeometry):
     _init_func = capi.create_linestring
     _minlength = 2
+    has_cs = True
 
     def __init__(self, *args, **kwargs):
         """
diff --git a/django/contrib/gis/geos/point.py b/django/contrib/gis/geos/point.py
index e53a4569bf..65cf1344c9 100644
--- a/django/contrib/gis/geos/point.py
+++ b/django/contrib/gis/geos/point.py
@@ -10,6 +10,7 @@ from django.utils.six.moves import range
 class Point(GEOSGeometry):
     _minlength = 2
     _maxlength = 3
+    has_cs = True
 
     def __init__(self, x, y=None, z=None, srid=None):
         """
diff --git a/django/contrib/gis/geos/prepared.py b/django/contrib/gis/geos/prepared.py
index 98ab1554ea..994082b296 100644
--- a/django/contrib/gis/geos/prepared.py
+++ b/django/contrib/gis/geos/prepared.py
@@ -1,6 +1,5 @@
 from .base import GEOSBase
 from .error import GEOSException
-from .geometry import GEOSGeometry
 from .libgeos import geos_version_info
 from .prototypes import prepared as capi
 
@@ -18,6 +17,7 @@ class PreparedGeometry(GEOSBase):
         # from being garbage collected which could then crash the prepared one
         # See #21662
         self._base_geom = geom
+        from .geometry import GEOSGeometry
         if not isinstance(geom, GEOSGeometry):
             raise TypeError
         self.ptr = capi.geos_prepare(geom.ptr)