Support environment variable inheritance from command-line

[eromoe]

My env like:

basefreq: 1m
train_start_date: "2020-08-11"
train_end_date: "2023-02-19"
test_start_date: "2023-02-19"
test_end_date: "2023-03-21"
autgoluon_model_dir: "{{root}}/AutogluonModels"
train_datemark : "#{{train_start_date}}~{{train_end_date}}"
train_test_datemark: "#{{train_start_date}}~{{train_end_date}}_{{test_start_date}}~{{test_end_date}}"

I was doing a walk forwarding train test

for a,b,c,d in split_dates('20200701', '20230319', 100, 30, 200):
    cmd = 'ploomber build --env--train_start_date %s --env--train_end_date %s --env--test_start_date %s --env--test_end_date %s' % (to_datestr(a), to_datestr(b), to_datestr(c), to_datestr(d))
    print(cmd)
    os.system(cmd)

Then I found train_datemark and train_test_datemark remain old env values.

[edublancas]

can you provide a reproducible example? I'm not following what you're expecting and what ploomber is doing

[edublancas]

ah. I think I now understand what you mean (based on this)

yeah, this looks like a bug, do you have time to submit a PR?

[eromoe]

Looks like target file is https://github.com/ploomber/ploomber/blob/8a9fccd14938d805941046d2d65d6cd6a8d9468e/src/ploomber/env/expand.py , I would take a look when have time