JSONDecodeError when trying an operation

Leandro-Zamudio — Tue, 25 Nov 2025 13:48:32 GMT

Hi.

I'm trying to use ArcGIS API for Python to run a simple query on two layers from the same service.

https://arcgisv11.sea.gob.cl/server/rest/services/WEBServices/ProyectosSEIA/MapServer

Using this sample code I try to create a dataframe from the layer data and it works the EIA layer (1) but not in DIA layer (2) even if the layers are almost identical

import pandas as pand from arcgis.gis import GIS from arcgis.features import GeoAccessor, GeoSeriesAccessor, FeatureLayerCollection gis = GIS() fs_url=r"https://arcgisv11.sea.gob.cl/server/rest/services/WEBServices/ProyectosSEIA/MapServer" coleccioncapas = FeatureLayerCollection(fs_url) Capas=coleccioncapas.layers #for capa in Capas: # print(capa.properties.name) capa_data=Capas[1] df_data = pand.DataFrame.spatial.from_layer(capa_data) print(df_data.head(5))

That's the error.

C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\urllib3\connectionpool.py:1097: InsecureRequestWarning: Unverified HTTPS request is being made to host 'arcgisv11.sea.gob.cl'. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/latest/advanced-usage.html#tls-warnings warnings.warn( C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\urllib3\connectionpool.py:1097: InsecureRequestWarning: Unverified HTTPS request is being made to host 'arcgisv11.sea.gob.cl'. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/latest/advanced-usage.html#tls-warnings warnings.warn( Traceback (most recent call last): File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\requests\models.py", line 974, in json return complexjson.loads(self.text, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\json\__init__.py", line 346, in loads return _default_decoder.decode(s) ^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\json\decoder.py", line 337, in decode obj, end = self.raw_decode(s, idx=_w(s, 0).end()) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\json\decoder.py", line 355, in raw_decode raise JSONDecodeError("Expecting value", s, err.value) from None json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0) During handling of the above exception, another exception occurred: Traceback (most recent call last): File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\features\geo\_accessor.py", line 2683, in from_layer return from_layer(layer=layer) ^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\features\geo\_io\serviceops.py", line 186, in from_layer sdf = layer.query(where=query, as_df=True) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\features\layer.py", line 2257, in query ).execute() ^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\_impl\common\_query.py", line 658, in execute return self._query(raw) ^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\_impl\common\_query.py", line 679, in _query return self._handle_query_exception(query_exception) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\_impl\common\_query.py", line 843, in _handle_query_exception raise query_exception File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\_impl\common\_query.py", line 677, in _query return self._process_query_result(result, raw) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\_impl\common\_query.py", line 711, in _process_query_result features = self._fetch_all_features_by_chunk() ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\_impl\common\_query.py", line 829, in _fetch_all_features_by_chunk result = future.result().json() ^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\requests\models.py", line 978, in json raise RequestsJSONDecodeError(e.msg, e.doc, e.pos) requests.exceptions.JSONDecodeError: Expecting value: line 1 column 1 (char 0) During handling of the above exception, another exception occurred: Traceback (most recent call last): File "d:\Code\core-python-jupiter\pruebas\testing.py", line 12, in <module> df_data = pand.DataFrame.spatial.from_layer(capa_data) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\site-packages\arcgis\features\geo\_accessor.py", line 2687, in from_layer raise Exception( Exception: Malformed response from server, could not load the dataset: Expecting value: line 1 column 1 (char 0)

Re: JSONDecodeError when trying an operation

AustinAverill — Thu, 08 Jan 2026 12:04:00 GMT

I have found that the pd.DataFrame.spatial.from_layer() method is wildly inconsistent and often has little-to-no helpful traceback for debugging when it randomly decides to work.

I would recommend using the query method on the layers instead. You can include the "as_df=True" argument or call the ".sdf" attribute of the queried featureset after the fact. When I tested just now, this method worked fine.

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JSONDecodeError when trying an operation

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