What can you do with a QGIS console?

What can you do with a QGIS console?

QGIS brings a Python API (see PyQGIS Developer Cookbook for some code sample) to let the user interact with its objects (layers, feature or interface). QGIS also has a Python console.

How is QGIS used in the Geospatial World?

As you will see later in this chapter, QGIS has been designed with a plugin architecture. Plugins can be written in Python, a very famous language in the geospatial world. QGIS brings a Python API (see PyQGIS Developer Cookbook for some code sample) to let the user interact with its objects (layers, feature or interface).

How to execute code snippets in pyqgis cookbook?

Open PyQGIS Cookbook by typing _pyqgis. You can execute code snippets from the output panel by selecting some text and pressing Ctrl+E. No matter if selected text contains the interpreter prompt ( >>>, ). Use the Show editor button to enable the editor widget.

Where do I find my command history in QGIS?

Ctrl+Shift+Space to view the command history: double-clicking a row will execute the command. The Command History dialog can also be accessed from context menu of input area; Save and clear the command history. The history will be saved into the file ~/.qgis2/console_history.txt; Open PyQGIS Cookbook by typing _pyqgis.

How to execute code snippets in QGIS Python?

Execute code snippets from the output area using the Enter selected from the contextual menu or pressing Ctrl+E; Browse the command history from the input area using the Up and Down arrow keys and execute the command you want; Ctrl+Shift+Space to view the command history: double-clicking a row will execute the command.

How to open the interactive console in Python?

To open the console go to Plugins ‣ Python Console ( Ctrl+Alt+P ). The interactive console is composed of a toolbar, an input area and an output one.

How to create and export print layouts in Python for QGIS?

So in the previous code I created a map, which is a QgsLayoutItemMap object. My apologies but the map.setRect () method confuses me and to be honest, I can’t explain what it does or why its there.

How to create and print a map layout in Python?

First, once you’ve written the initial code to set up the map, you can change map symbology or map layers and exactly replicate layout. Second, once you have the script developed you can create a map at the click of a button. You only have to develop a layout once, and don’t have to worry about accidentally making changes to it.

Why do you need pyqgis to create a map?

There are two reasons this is really awesome! First, once you’ve written the initial code to set up the map, you can change map symbology or map layers and exactly replicate layout. Second, once you have the script developed you can create a map at the click of a button.

Which is the runalg method in QGIS API?

To do so, you can use QGIS API commands, or, even easier, use one of the handy methods provided for such tasks. The runalg method returns a dictionary with the output names (the ones shown in the algorithm description) as keys and the file paths of those outputs as values.

How to install a Python library in QGIS 3?

Installing Python packages in QGIS 3 (for Windows) 1 Open OSGeo4W shell (packed with QGIS in the start menu) 2 Type py3_env. This should print paths of your QGIS Python installation. 3 Use Python’s pip to install the library of your choice: python -m pip install {your library}

Can you install rasterio and NumPy on QGIS?

Actually rasterio and numpy were installed in it’s main system Python (C:\\Python27), but I need QGIS Python to recognize it. QGIS, as distributed by OSGeo4W, usually comes with its own Python installation and its own packages that are independent of your “regular” Python installation.

Where do I find plugin manager in QGIS?

Core plugins are already part of the standard QGIS installation. To use these, you just need to enable them. Open QGIS. Click on Plugins ‣ Manage and Install Plugins…. to open the Plugin Manager dialog. Even if this is your first time using QGIS, you will see a lot of plugins listed under the Installed tab.

How to read the attribute values using pyqgis?

Once you have a QgsFeature object you can use the attributes () method to retrieve the attributes (a.k.a. columns or fields) associated with that feature (a.k.a. row), e.g.: If you want to index the field by it’s name, rather than a number, you need to use the field mappings:

How to move layers in the layer order panel using pyqgis?

To automatically move newly added layers to the top of Layer Order Panel, you could use the legendLayersAdded SIGNAL (this signal is appropriate because it’s emitted after the Layer Order Panel gets the new layer) from QgsMapLayerRegistry and reorder layers in this way:

What happens if somebody edits the same feature in QGIS?

This version of QGIS does not track if somebody else is editing the same feature at the same time as you are. The last person to save its edits wins. For an optimal and accurate edit of the vector layer geometries, we need to set an appropriate value of snapping tolerance and search radius for features vertices.

What happens if you dont snap vertices in QGIS?

If you aren’t within the snapping tolerance, QGIS will leave the vertex where you release the mouse button, instead of snapping it to an existing vertex and/or segment. The snapping tolerance setting affects all tools that work with tolerance.

How to debug QGIS using PyScripter IDE?

Debugging using Pyscripter IDE (Windows) ¶ For using Pyscripter IDE , here’s what you have to do: Make a copy of qgis-unstable.bat and rename it pyscripter.bat. Open it in an editor. And remove the last line, the one that starts QGIS.

Where to find remote debugging plugins in QGIS?

There is some preparation to be done on QGIS itself. Two plugins are of interest: Remote Debug and Plugin reloader. Go to Plugins ‣ Manage and Install plugins… Search for Remote Debug ( at the moment it’s still experimental, so enable experimental plugins under the Options tab in case it does not show up).

How to fix QGIS importerror in Python 2.7?

Make a copy of qgis-unstable.bat and rename it pyscripter.bat. Open it in an editor. And remove the last line, the one that starts QGIS. Add a line that points to your Pyscripter executable and add the commandline argument that sets the version of Python to be used (2.7 in the case of QGIS >= 2.0)

How to get a QGIS layer from a table?

More information can be found in the classes under the processing/tools package, and also in the example scripts provided with QGIS. getObject (obj): Returns a QGIS object (a layer or table) from the passed object, which can be a filename or the name of the object in the QGIS Layers List

What is the purpose of SUDs in Python?

Suds is a lightweight SOAP python client that provides a service proxy for Web Services.

How to debug SOAP messages in SUDS PY3?

A common example (show sent/received soap messages): Suggested modules for debugging: Set the logging level to ‘DEBUG’ on this module to see soap messages (in & out) and http headers. Set the logging level to ‘DEBUG’ on this module to see more details about soap messages (in & out) and http headers.

How to iterate over layers in pyqgis Python?

Then you can iterate over layers like: Because .mapLayers () returns a dictionary ( dict ), you can also use .values () method of dictionary which returns just a list which contains layers in that case. Then you can iterate over layers like: Note: After grouping I have to remove the duplicate layer so I used root.removeLayer (lyr).