Importing .py script to action editor using QGIS

Question

I import a .py file like so:

import sys
sys.path.append('/foo/bar/boo/far/')
# import foobar.py from target folder
import foobar

This line (simplified for sharing) works when the code is typed directly in the action editor window instead of importing the external script:

ft = lyr.getFeature([% $id %])

But when I use the same line in the external script, a syntax error is being thrown:

 ft = lyr.getFeature([% $id %])
 ^
SyntaxError: invalid syntax

I continued with direct coding inside the action editor, which is possible of course, but working with an external script would significantly save time!

Any thoughts?

Answer 1

[% $id %] is special QGIS syntax for "before sending this text as code to the Python interpreter, insert the value of the QGIS expression $id" here.

A Python interpreter does not know about QGIS' special [%%] syntax and thus will stumble.

You will need to provide the ID value in a normal Python way there.

• winnewoerp: Thank you! That definitely helps for finding a solution. I'm still (almost) a PyQGIS newbie. Is iface the way to go here, using iface.activeLayer() to access the action's layer? And is there an iface way to access the clicked feature? I tried to find "a normal Python way" but did not find it so far.
• Matt: Please create new questions (one question per question) for your other enquiries, as they have no relation to your original post here. It helps to keep Questions and Answers concise and to the point, otherwise things will become jumbled.
• winnewoerp: Thanks, Matt. That's what I did now: https://gis.stackexchange.com/questions/458133/identify-clicked-feature-in-external-python-script-for-qgis-layer-action