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<p class="MsoNormal">Hello QGIS developers,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have a problem where I am calling a processing algorithm with Python not releasing file handles.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The smallest reproducible code sample and work flow does the following:
<o:p></o:p></p>
<ol style="margin-top:0cm" start="1" type="1">
<li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo1">Calls the native:rasterlayerzonalstatistics processing algorithm on a raster layer by adding it as a task through QgsApplication task manager<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo1">The callback is invoked as expected, the statistics file is generated<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo1">Remove the original layer in QGIS layers pane because you didn’t like it/you want to do it again for whatever reason. It seems to be removed successfully.<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo1">Now in file explorer, try to delete the layer file – get “file in use” error that won’t go away until you close QGIS<o:p></o:p></li></ol>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I see on stackoverflow this is intermittently reported <a href="https://gis.stackexchange.com/questions/433300/deleting-folder-and-processed-files-in-qgis-using-pyqgis">
<span style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;background:white;text-decoration:none">https://gis.stackexchange.com/questions/433300/deleting-folder-and-processed-files-in-qgis-using-pyqgis</span></a> and
<a href="https://gis.stackexchange.com/questions/243520/deleting-raster-file-after-doing-some-processing-in-qgis">
<span style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;background:white;text-decoration:none">https://gis.stackexchange.com/questions/243520/deleting-raster-file-after-doing-some-processing-in-qgis</span></a> but have only seen workarounds.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The files for the QGIS workspace that reproduces the problem is uploaded here:
<a href="https://blightanner-my.sharepoint.com/:f:/g/personal/lauren_yang_blightanner_com_au/EvQ-xHtnXINFigK0FutFjngBxGKOlOB7M8pKVNYTAX4d5Q?e=sn9geF">
<span class="MsoSmartlink"><img border="0" width="16" height="16" style="width:.1666in;height:.1666in" id="Picture_x0020_7" src="cid:image007.png@01D937C4.34CDCAC0" alt="Folder icon"> QGISProcessingFileHandles</span></a> To reproduce the problem, in the python
console of QGIS type exec(open('processFileSnippet.py').read())<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’m not sure if I’m not calling the processing algorithm correctly or not closing file handles when I should be. If the link above doesn’t work, I can provide the python file snippet and supporting raster file.<o:p></o:p></p>
<p class="MsoNormal">Other details - OS: Windows 10 64 bit, QGIS version 3.22.5, Python 3.9.5<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any insight would be appreciated.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Lauren<o:p></o:p></p>
<p><b><span style="font-size:10.5pt;color:black">Lauren Yang</span></b><b><span style="font-size:8.0pt;color:black"><br>
</span></b><span style="font-size:10.5pt;color:#333333">Civil and Water Engineer</span><o:p></o:p></p>
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