Extend pyhps python examples to return output parameters in exec script

[ojkoenig]

To make use of new functionality to pass parameters back via context of exec script as defined here we propose to extend existing examples in pyhps with that option.

Most prominent candidates for that are the existing python examples that already create json files with input and outputs.
These examples can now be extend to provide an option where the json files are created/loaded directly from the exec script, passing/reading parameters in there instead of using the parameter mappings.

We propose to implement this as a new option, also keep old mechanism, expose option as cmd-line argument in the project_setup.py script.

[engpas]

The examples to be extended are:

• python_two_bar_truss_problem
  • Extend tests to cover more branches of this example
• python_multi_process_step
  • Think again about what exactly should be supported by the new paths
  • Add param-transfer CLI argument
  • Support parallel execution
  • Support sequential execution
  • Fix job task changing functionality
  • Support job task changing with execution script
• python_linked_multi_process_step
  • Add --unmapped-params CLI argument
  • Add execution script
  • Adjust task definition in case of execution script
  • In execution script, extract execution level from input script file name
  • In execution script, use out param of previous task as input param for next task
  • Pass param as .json to eval.py
  • Read output from .json written by eval.py
• Add test for python_linked_multi_process_step in test_examples.py

[engpas]

For python_multi_process_step, the logic is the following:

• Add new flags --param-transfer, --use-exec-script
• Set param_transfer string parameter
• For exec_script:
  • Add images bool parameter
  • Enable exec script in task
  • In exec script, detect execution level from eval script name
  • In exec script, detect if eval script contains CALL_SUBSCRIPT = True
  • If --param-transfer=json_file:
    • Don't define the files td{i}_input.json, td{i}_output.json
    • If CALL_SUBSCRIPT detected, generate the sub_td_{i}_input.json input file in the exec script
    • In task_files.py, don't define sub_td{i}_input.json
• Fix file changing by removing the extra underscore in sub_td_{i}

[engpas]

There still seems to be a bug in python_mult_process_step, need to have another look. But overall, the functionality is there.

[engpas]

All known issues are fixed, PR is ready

[engpas]

Rolled back changes on python_multi_process_step, python_two_bar_truss_problem and python_linked_multi_process_step except for fixes, as per decision taken today. Made a new python_two_bar_truss_unmapped example, that showcases how one can use unmapped parameters.