Rendered Templates - py renderer doesn't work for list or dict

Apache Airflow version: 2.1.1

What happened:

The rendered templates screen doesn’t show the operator arguments for TaskFlow API operators.

What you expected to happen:

Should show the arguments after any templates have been rendered.

How to reproduce it:

Will happen for any @task decorated operator.

Anything else we need to know:

This issue appears on a number of operators. Possible solution is to modify the “get_python_source” in utils/code_utils.py to handle list and dict. This would cause any operator that using py as the renderer to handle lists and dicts. Possibly something like:

    if isinstance(x, list):
        return [str(v) for v in x]

    if isinstance(x, dict):
        return {k: str(v) for k, v in x.items()}

The converting values to strings seems necessary in order to avoid errors when this is passed to the pygments lexer.

[brain-buster]

@brain-buster - would you like to make a PR to fix the issue maybe ?

Yes, of course. I will make PR tomorrow ASAP since this bug is completely affects my project.

[potiuk]

@brain-buster - would you like to make a PR to fix the issue maybe ?