[QGIS-Developer] Reg: QgsCoordinateTransform not working on Linux

[Ujaval Gandhi]

You are not initializing QGIS in your script. Try adding this at the
beginning of your script

from qgis.core import QgsApplication

qgs = QgsApplication([], False)
qgs.initQgis()

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Ujaval Gandhi
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On Thu, May 27, 2021 at 6:27 PM Prem Kumar <prem.netgis at gmail.com> wrote:

> Hi Team,
>
> Just wondering whether I'm missing something or a genuine bug, please
> advise below.
>
> All I am trying is, to take the geometry object in json format whose CRS
> is in WGS84 (EPSG:4326) and transform the geometry to EPSG:3857 CRS and
> eventually use it in further processing because rest of the processing is
> in EPSG:3857 CRS.
>
> I have written below code and it works like a charm on Windows 10 but it
> doesn't transform the geometry on Linux. Please advise if there is anything
> wrong or missing to add.
> *Code Snippet for reproducing:*
>
> from qgis.PyQt.QtCore import QVariant
> from shapely.geometry import shape
> import geojson,json
> from qgis.core import (QgsGeometry,QgsCoordinateReferenceSystem,QgsCoordinateTransform,QgsProject)
> from shapely import speedups as sups
> sups.disable()
>
> in_geometry='[{"type": "LineString","coordinates": [[-78.85338577199997,43.85845267000008],[-78.85593885699996,43.857924291000074]]}]'
> geomjson = json.loads(in_geometry)
> old_crs = QgsCoordinateReferenceSystem("EPSG:4326")
> new_crs = QgsCoordinateReferenceSystem("EPSG:3857")
> xtransform = QgsCoordinateTransform(old_crs, new_crs, QgsProject.instance())
> for i, g in enumerate(geomjson):
>     s = json.dumps(g)
>     g1 = geojson.loads(s)
>     shapely_geom = shape(g1)
>     qgs_geom=QgsGeometry.fromWkt(shapely_geom.wkt)
>     qgs_geom.transform(xtransform)
>     print (qgs_geom)
>
> *Output from Pycharm:*
> C:\Qgis\apps\Python37\python.exe C:/_WORK/SERVICE/test_transform.py
> <QgsGeometry: LineString (-8777918.77684544585645199
> 5443563.52439526654779911, -8778202.97550544328987598
> 5443481.85537817236036062)>
>
> Process finished with exit code 0
>
> *Output from Linux terminal:*
> (gisenv) admin at rd-temp-server:~/gis_service$ python3 test_transform.py
> Application path not initialized
> Application path not initialized
> <QgsGeometry: LineString (-78.85338600000000042 43.85845299999999725,
> -78.85593900000000644 43.85792399999999702)>
> (gisenv) admin at rd-temp-server:~/gis_service$
>
> Thanks.
> -Prem
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