topic Re: __geo_interface__ Generates Different and Incorrect Output When ArcPy Not Installed in ArcGIS API for Python Questions

__geo_interface__ Generates Different and Incorrect Output When ArcPy Not Installed

JoshuaBixby — Sun, 12 Dec 2021 09:59:07 GMT

Hey ArcGIS API for Python staff on GeoNet, I found a bug for you.

It turns out the __geo_interface__ methods generate different, and incorrect, output when ArcPy is not installed along with ArcGIS API for Python.

>>> from arcgis.geometry import Geometry
>>> from pprint import pprint
>>>
>>> # simple square with a hole in the middle
... json = {
...     "rings": [
...         [
...             [0, 0],
...             [0, 10],
...             [10, 10],
...             [10, 0],
...             [0, 0]
...         ],
...         [
...             [3, 3],
...             [7, 3],
...             [7, 7],
...             [3, 7],
...             [3, 3]
...         ]
...     ],
...     "spatialReference": {
...         "wkid": 3857
...     }
... }
>>>
>>> # __geo_interface__ output when ArcPy is installed
>>> pprint(Geometry(json).__geo_interface__)
{'coordinates': [[[(0.0, 0.0),
                   (0.0, 10.0),
                   (10.0, 10.0),
                   (10.0, 0.0),
                   (0.0, 0.0)],
                  [(3.0, 3.0),
                   (7.0, 3.0),
                   (7.0, 7.0),
                   (3.0, 7.0),
                   (3.0, 3.0)]]],
 'type': 'MultiPolygon'}
>>>
>>> # __geo_interface__ output when ArcPy is not installed
>>> pprint(Geometry(json).__geo_interface__)
{'coordinates': [[[(0, 0),
                   (0, 10),
                   (10, 10),
                   (10, 0),
                   (0, 0)]],
                 [[(3, 3),
                 (7, 3),
                 (7, 7),
                 (3, 7),
                 (3, 3)]]],
 'type': 'MultiPolygon'}
>>>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Notice when ArcPy is not installed, the __geo_interface__ output contains an extra closing bracket on the outer ring of the polygon, thus turning a single-part polygon with a hole into a overlapping multi-part polygon.

Re: __geo_interface__ Generates Different and Incorrect Output When ArcPy Not Installed

DanPatterson_Retired — Wed, 07 Mar 2018 21:36:47 GMT

And float vs integer as well.

Re: __geo_interface__ Generates Different and Incorrect Output When ArcPy Not Installed

JoshuaBixby — Sun, 12 Dec 2021 09:59:10 GMT

Some additional information for the ArcGIS API for Python team. This issue affects any geometry properties or methods that rely on Shapely when ArcPy is not installed:

>>> from arcgis.geometry import Geometry
>>>
>>> # simple square with a hole in the middle
>>> json = {
...     "rings": [
...         [
...             [0, 0],
...             [0, 10],
...             [10, 10],
...             [10, 0],
...             [0, 0]
...         ],
...         [
...             [3, 3],
...             [7, 3],
...             [7, 7],
...             [3, 7],
...             [3, 3]
...         ]
...     ],
...     "spatialReference": {
...         "wkid": 3857
...     }
... }
>>>
>>> geom = Geometry(json)
>>> 
>>> geom
{'spatialReference': {'wkid': 3857}, 'rings': [[[0, 0], [0, 10], [10, 10], [10, 0], [0, 0]], [[3, 3], [7, 3], [7, 7], [3, 7], [3, 3]]]}
>>> type(geom)
<class 'arcgis.geometry._types.Polygon'>
>>> 
>>> # geometry properties that don't rely on Shapely when ArcPy is not installed
>>> geom.point_count
10
>>> geom.part_count
2
>>> geom.is_multipart
False
>>> 
>>> # geometry properties that do rely on Shapely when ArcPy is not installed
>>> geom.area
ParseException: Expected number but encountered ','
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\...\Continuum\miniconda3\envs\arcgis\lib\site-packages\arcgis\geometry\_types.py", line 585, in area
    return self.as_shapely.area
  File "C:\...\Continuum\miniconda3\envs\arcgis\lib\site-packages\arcgis\geometry\_types.py", line 517, in as_shapely
    return wkt.loads(self._wkt())
  File "C:\...\Continuum\miniconda3\envs\arcgis\lib\site-packages\shapely\wkt.py", line 10, in loads
    return geos.WKTReader(geos.lgeos).read(data)
  File "C:\...\Continuum\miniconda3\envs\arcgis\lib\site-packages\shapely\geos.py", line 254, in read
    "Could not create geometry because of errors "
shapely.errors.WKTReadingError: Could not create geometry because of errors while reading input.
>>> ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

The bad code appears to be in __geo_interface__ property of arcgis.geometry._types .

Re: __geo_interface__ Generates Different and Incorrect Output When ArcPy Not Installed

RohitSingh2 — Tue, 27 Mar 2018 05:09:51 GMT

Thanks for letting us know. We've created a bug report and will look into fixing these issues.

Re: __geo_interface__ Generates Different and Incorrect Output When ArcPy Not Installed

JoshuaBixby — Tue, 04 Sep 2018 13:14:06 GMT

I have confirmed this is fixed in version 1.5