New command line parameter --py-args

[domi4484]

This PR will allow to pass arguments to the script provided via --code parameter and more generally to each python execution. All arguments after --py-args till -- are passed over to the python interpreter and ignored by QGIS.

Note: After --code-args is not possible to pass any other parameter than -- to QGIS

For example:

qgis --code /home/domi/test.py --py-args --specialScriptArguments "a text arg" 'and another arg' -- layer1 layer2

• test.py will have this content in sys.argv: ['/home/domi/test.py', '--specialScriptArguments', 'a text arg', 'and another arg']
• layer1 and layer2 will be normally handled by QGIS as layers to load

[domi4484]

I think this is not the best way to pass an array from c++ to python. Do someone know a better way?

[m-kuhn]

Could you make this a raw string r'...' and escape any ' in the string?

[qgis-bot]

@domi4484
This pull request has been tagged as requiring documentation.

A documentation ticket will be opened at https://github.com/qgis/QGIS-Documentation when this PR is merged.

Please update the description (not the comments) with helpful description and screenshot to help the work from documentors.
Also, any commit having [needs-doc] or [Needs Documentation] in will see its message pushed to the issue, so please be as verbose as you can.

Thank you!

[qgis-bot]

@domi4484
A documentation ticket has been opened at qgis/QGIS-Documentation#9544
It is your responsibility to visit this ticket and add as much detail as possible for the documentation team to correctly document this change.
Thank you!