Implement bash translator

[kdm9]

Support translation of parameters to bash/*NIX shell

Thanks for papermill! I have used it for python notebooks, but a lot of my work is best done in shell, for which I use jupyter notebooks with the bash_kernel (via *.sh scripts and jupytext).

Alas papermill doesn't seem to support bash/shell script, due to a hitherto unimplemented bash translator. This PR implements a BashTranslator, and therefore enables bash kernel notebooks to be parametrised. This code supports str, list, bool¹, None, int, and float parameter values. Dict could in theory be supported via associative arrays but for now they are not implemented².

For a functioning example, please see the attached notebook.

Best,
K

Footnotes

1. Bash doesn't really have a bool type, but true and false are at least common and sensible string constants for truthy-ness and falsy-ness. See for example this SO answer. ↩

2. Associative arrays require quite recent bash versions, and I've never seen them used outside tutorials. Supporting them would also likely require a more involved code path as one must pre-declare an associative array in bash, and then declare one entry per line (see link above). ↩

[kdm9]

Alas GH doesn't support attaching *.ipynb, so I have had to rename it *.txt, but here's the test notebook.

test.ipynb.txt

The following params.yml can be used with this:

say: "Write a book"
people:
  - Alice
  - Bob
  - Robert'); DROP TABLE students;-- # XKCD's favourite son

[kdm9]

A friendly ping to the nteract team about this PR. All tests pass locally, and this is currently blocking us from using papermill in our analyses.

[rohitsanj]

Thanks for the PR, @kdm9! Can you please add some tests to test_translators.py.

[kdm9]

@rohitsanj tests implemented and passing. There are some unrelated failures on my machine, all to do with the google cloud interaction, which I assume is because I don't have a GCS environment correctly configured. Any chance you can allow the CI to run on this PR, so we can see if all is green in a well-configured environment?

[codecov]

Codecov Report

Merging #674 (000a80a) into main (98013f0) will increase coverage by 0.13%.
The diff coverage is 90.90%.

@@            Coverage Diff             @@
##             main     #674      +/-   ##
==========================================
+ Coverage   91.72%   91.86%   +0.13%     
==========================================
  Files          17       17              
  Lines        1583     1622      +39     
==========================================
+ Hits         1452     1490      +38     
- Misses        131      132       +1     

Impacted Files	Coverage Δ
papermill/translators.py	98.38% <90.90%> (-0.48%)	⬇️
papermill/parameterize.py	97.91% <0.00%> (-0.05%)	⬇️
papermill/execute.py	100.00% <0.00%> (ø)
papermill/engines.py	98.37% <0.00%> (+0.09%)	⬆️
papermill/iorw.py	81.15% <0.00%> (+0.91%)	⬆️

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[MSeal]

Thanks for adding tests! They passed on the CI chain so no worries about local dev issues there

Review request satisfied