How to load a project into QGIS with pyqgis?

How to load a project into QGIS with pyqgis?

I have been able to load layers ok using little scripts but no luck loading a project into QGIS. I keep getting a ‘SyntaxError: invalid syntax’ for line 13. I am using the Python Console inside QGIS and type in ‘import _loadproject’ to start the script. Can someone point out where I am going wrong?

How to load a WMS layer using pyqgis?

Answer can be found here: https://gis.stackexchange.com/questions/120823/how-to-load-a-wms-layer-using-pyqgis. Basically, it is just a version problem. If you have qgis previous than v2.6, it would not work. But it is fixed for 2.6 If it is still not working for you, you most likely have problem for environment variable settings.

How to customize the QGIS interface in Python?

We will also explore GUI programming techniques for customizing the QGIS interface using Qt widgets. This course requires basic knowledge of Python. If you are not familiar with Python, it is strongly recommended you complete our Python Foundation for Spatial Analysis course. We will build upon the exercises covered in that course.

Where do I Enter my Password to launch QGIS?

Click the Lock icon and enter your password. Click the Open Anyway button to launch QGIS. This step needs to be done only once. The next time, you can launch QGIS-LTR directly from the Applications folder. The code examples in this class use a variety of datasets.

Where do I find Python console in QGIS?

If you don’t have QGIS running at the moment, please start it up and open the Python console from the Plugins menu in the main menu bar. When you open the Python console in QGIS, the Python qgis package and its submodules are automatically imported as well as other relevant modules including the main PyQt5 modules.

Do you need to instantiate qgslayermapcanvasbridge in QGIS standalone?

If you are writing a QGIS standalone application, in order to synchronise the loaded project with the canvas you need to instantiate a QgsLayerTreeMapCanvasBridge as in the example below: 2.1. Resolving bad paths ¶

How to draw country polygons in QGIS 4.5?

Here we create an object of the QgsGraduatedSymbolRenderer class that we want to use to draw the country polygons from our layer using a graduated color approach based on the population attribute ‘POP2005’. The name of the field to use is set via the renderer’s setClassAttribute () method in line 2.

How to define the extent of a QGIS map?

Currently I am just using the simple rendering technique outlined here: http://www.qgis.org/pyqgis-cookbook/composer.html#simple-rendering I have failed, however, at adapting this code to define a specific extent. I provide the code below. The only examples that I can find that show how to change extent involve creating a MapCanvas.

How to make a pyqgis script with osgeo4w?

An essential first step is to ensure that all environment variables are set correctly. The most reliable approach is to go to C:\\OSGeo4W64\\bin (or wherever OSGeo4W is installed on your machine), make a copy of qgis-dev-g7.bat (or any other QGIS version that you have installed) and rename it to pycharm.bat:

How to make a PNG map in Python?

Making use of mapCanvas () doesn’t add too many lines of code and would export a simple PNG. From the python console, this code would produce a simple screen capture of the area oriented around a selected feature, all active layers, and any activated labels:

Where do I set the path to layers in QGIS?

In the properties window for the project under Settings ‣ Project Properties (kde) or Project ‣ Project Properties (Gnome, OS X or Windows), you can set project-specific options. set whether the path to layers in the project should be saved as absolute (full) or as relative to the project file location.

How are the environment variables shown in QGIS?

Already-defined environment variables are displayed in Current environment variables, and it’s possible to filter them by activating Show only QGIS-specific variables. Copy features as ‘Plain text, no geometry’, ‘Plain text, WKT geometry’, or ‘GeoJSON’ when pasting features in other applications.

Where do I find the QGIS settings menu?

QGIS is highly configurable through the Settings menu. Choose between Project Properties, Options and Customization. QGIS follows desktop guidelines for the location of options and project properties item. Consequently related to the OS you are using, location of some of items described below could be in the Project or the Settings menu.

Do you need QGIS to run a python script?

While that is helpful, many times you need a way to run this jobs via the command-line and without needing to open QGIS. Fortunately, you can write standalone python scripts that use QGIS libraries and can be run via the command-line.

Is there a way to automate tasks in QGIS?

You can automate a lot of tasks in QGIS using Python scripting (PyQGIS) and the Processing Framework. Most of the time, you would run these scripts manually while QGIS is open. While that is helpful, many times you need a way to run this jobs via the command-line and without needing to open QGIS.

How to run any processing algorithm via pyqgis?

Running any Processing algorithm via PyQGIS. Fixing topological errors in a vector layer. Geofabrik provides daily updated shapefiles of OpenStreetMap datasets. We will use shapefiles for Fiji for this exercise. Download the fiji-latest.shp.zip and unzip it to a folder on your disk.

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.

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.

What does the setpathpreprocessor do in QGIS?

The QgsPathResolver class with the setPathPreprocessor () allows setting a custom path pre-processor function, which allows for manipulation of paths and data sources prior to resolving them to file references or layer sources.

How to get list of layer names using pyqgis?

I need a list containing the names of all the layers in a QGIS session. I did the task as but this has the problem that only the names for the visible layers are extracted.

How to manage layers in a qgsproject?

These are the basics of managing layers in a QgsProject. PyQGIS 101 is a work in progress. I’d appreciate any feedback, particularly from beginners! Loading…

When to use qgsproject.instance instead of QGIS?

Most of the time you want to use QgsProject.instance () instead as many components of QGIS work with the singleton. Reads and writes project states. Has two general kinds of state to make persistent.

Where do I find QGIS-LTR in Python?

The next time, you can launch QGIS-LTR directly from the Applications folder. The code examples in this class use a variety of datasets. All the required layers, project files, icons etc. are supplied to you in the pyqgis_in_a_day.zip file.

Where do I find the console in QGIS?

The QGIS Python Console window can be accessed by using the Python Console item in the Plugins menu. When you select this command, the Python Console will appear in the lower-right corner of the QGIS window. Here’s what the Python Console looks like when you first open it:

What can you do with fmeobjects in Python?

After importing fmeobjects, you will be able to read any supported data format (e.g. create a reader) and then write its features into any supported format (e.g. create a writer). The reader object is similar to the arcpy.da.SearchCursor (); it’s an iterator that you can go through just once reading features.

How to add fmeobjects to path in FME?

* add fmeobjects to your path: this can be done in various ways; the one I found the most useful is to use the sys.path.append and specifying the path to the FME Python installation. The file we have to import from this folder is the fmeobjects.pyd which is essentially a Windows .dll folder.

Is it possible to use FME in Python?

FME is a great ETL software that can help streamline various GIS workflows. One of the neat features about FME that I like most is that it’s possible to call FME workbenches (think of workbenches as of ArcGIS ModelBuilder models) from Python supplying input arguments.

How to write a python script in QGIS?

In the main QGIS window, go to Plugins ‣ Python Console. Once the console is open, find your script in the Processing Toolbox and double-click it to launch it. Select SUBREGION as the dissolve field. You may choose any field as the sum field as the script doesn’t have any code yet to deal with it.

How to write new processing algorithms in QGIS?

Within QGIS, you can use Create new script in the Scripts menu at the top of the Processing Toolbox to open the Processing Script Editor where you can write your code. To simplify the task, you can start with a script template by using Create new script from template from the same menu.

What can you do with QGIS as a beginner?

QGIS has a powerful programming interface that allows you to extend the core functionality of the software as well as write scripts to automate your tasks. QGIS supports the popular Python scripting language. Even if you are a beginner, learning a little bit of Python and QGIS programming interface…