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How to use pyqgis as an application in Python?
Consulting the PyQGis documentation, you’ll find that there are four main ways to utilize the PyQGis API: outside QGIS (in the Python shell or creating an applications with PyQt4 and not Tkinter (why import Tkinter twice ?) you can use PyQGIS as any other Python module. But Python does not know where to find PyQGIS.
What’s the difference between QGIS and standalone applications?
This leads me to believe that the difference is that the QGIS application correctly sets external environment variables, but those variables are not set properly when I run it as a standalone script.
Do you need PyQt4, Tkinter, or QGIS?
You don’t need here PyQt4, Tkinter or qgis.gui: you can create an application. You need here PyQt4 (and not Tkinter) and qgis.gui. I would like to program a standalone application using PyQGIS the way I can already program standalone applications using ArcPy.
Why is my standalone script not importing QGIS?
The issue does not appear to be that I have failed to import some Python package automatically imported by the QGIS application (qgis.core and qgis.utils) – I have those import statements in my standalone script, along with all the other package imports the script requires.
What happens when I run a standalone pyqgis script?
When I run the script in the console editor, it does it all correctly. When I run it as a standalone, it creates a window, then immediately destroys it, while throwing no errors. So the intepreter understands everything I’m asking the script to do – it just won’t do it.
Where to search for QGIS libraries and appropriate Python modules?
You will need to tell your system where to search for QGIS libraries and appropriate Python modules if they are not in a well-known location — otherwise Python will complain: This can be fixed by setting the PYTHONPATH environment variable. In the following commands, qgispath should be replaced with your actual QGIS installation path:
How to replace qgispath with pyqgis installation path?
In the following commands, qgispath should be replaced with your actual QGIS installation path: The path to the PyQGIS modules is now known, however they depend on qgis_core and qgis_gui libraries (the Python modules serve only as wrappers).
Where to find QGIS installer on a Mac?
On Linux this will be the directory containing the bin, lib, and share subdirectories of the QGIS install (possible locations include /usr and /usr/local): On Mac OS X, a likely location (depending on where you installed QGIS) will be:
What can you do with QGIS as an API?
Almost every operation that you can do using QGIS – can be done using the API. This allows developers to write code to build new tools, customize the interface and automate workflows. Let’s try out the API to perform some GIS data management tasks.
Can you use ArcPy outside of QGIS on Windows?
Because you use the Python version of ArcGIS, in other cases, the same is true, look using arcpy outside arcmap or Configure PyScripter to use with QGIS (and still use arcpy) on Windows, for example. You don’t need here PyQt4, Tkinter or qgis.gui: you can create an application. You need here PyQt4 (and not Tkinter) and qgis.gui.
How to create a GIS application using QGIS?
Lines 63-82 setup the main method and contain the code needed initialize and run our application. In line 65 we create a QApplication (a Qt class). In lines 68 and 69 we setup the QgsApplication object by setting the path to the QGIS installation and initializing QGIS.