Populating attribute table string field with the features JSON geometry string (but excluding CRS) in ArcGIS Pro

Question

Wondering if anyone can assist. I have a need to have the JSON geometry string of my features written into a text field of the features attribute table. Currently I use Calculate Field and then with Expression Type set as Python 3, I use !Shape!.JSON to get the geometry of my shape written in the JSON format.

An example of the output is as below:

{"paths":[[[532598.86840000004,180156.41719999909],[532598.97449999955,180156.3571000006],[532599.06400000025,180156.30650000088],[532599.91660000011,180155.82430000044],[532600.00329999998,180155.77520000003],[532601.43379999977,180154.96600000001],[532601.49770000018,180154.92980000004],[532601.52730000019,180154.91300000064],[532601.59130000044,180154.87680000067],[532601.62550000008,180154.85749999993],[532601.81120000035,180154.75239999965],[532601.91069999989,180154.70790000074],[532602.01410000026,180154.68319999985],[532602.11649999954,180154.67769999988],[532602.22149999999,180154.69099999964],[532606.99629999977,180155.82829999924],[532610.7949000001,180156.73310000077],[532611.03139999975,180156.79880000092],[532611.28399999999,180156.89069999941],[532611.66770000011,180157.07819999941],[532611.98379999958,180157.28370000049],[532612.27969999984,180157.52869999968],[532612.59509999957,180157.86690000072],[532612.81230000034,180158.16840000078],[532612.99129999988,180158.48660000041],[532613.12820000015,180158.80629999936],[532613.21600000001,180159.08269999921],[532613.27099999972,180159.32069999911],[532613.31290000025,180159.60600000061],[532613.32870000042,180159.8423999995],[532613.32699999958,180160.08899999969],[532613.3088999996,180160.31799999997],[532613.27969999984,180160.51909999922],[532612.90199999977,180162.50180000067],[532612.82749999966,180162.96209999919],[532612.73489999957,180163.53390000015],[532612.33550000004,180166.00210000016]]],"spatialReference":{"wkid":27700,"latestWkid":27700}}

However the resulting string has the coordinate system reference (in BOLD above) included at the end of the string. I need to be able to exclude the CRS information. I found a C# code example for exporting geometries to JSON which includes the ability to set an export flag to exclude the CRS info when writing the JSON string out. However I need to implement this in the Calculate Field environment using either Python 3 or Arcade.

Failing this being possible, in what environment would I be able to implement the C# code? Here is a link to the ESRI page with the example referred to above: https://pro.arcgis.com/en/pro-app/latest/sdk/api-reference/topic8167.html

Answer 1

You can convert the JSON string to a Python dictionary using json — JSON encoder and decoder - Python 3.x documentation, pop off the spatial reference item, and then convert back to JSON.

Something along the lines of:

import json

def strip_json_crs(shape_json):
    d = json.loads(shape_json)
    d.pop('spatialReference')
    return json.dumps(d)