Improve error message when NotebookRunner initialized with a String

[Zhenye-Na]

Description

This CR includes changes that make NotebookRunner initialized with a String explicitly throw an exception if the string looks like a pathlib.Path

Tests

$ pytest tests/sources/test_notebooksource.py -k 'test_error_if_source_str_like_path'
============================================================ test session starts ============================================================
platform linux -- Python 3.7.11, pytest-7.1.1, pluggy-1.0.0
rootdir: /home/vagrant/ploomber, configfile: pyproject.toml
plugins: cov-3.0.0, anyio-3.5.0
collected 87 items / 86 deselected / 1 selected

tests/sources/test_notebooksource.py .                                                                                                [100%]

================================================ 1 passed, 86 deselected, 1 warning in 0.32s ================================================

$ pytest tests/tasks/test_notebook.py  -k 'test_initialize_with_str_like_path'
============================================================ test session starts ============================================================
platform linux -- Python 3.7.11, pytest-7.1.1, pluggy-1.0.0
rootdir: /home/vagrant/ploomber, configfile: pyproject.toml
plugins: cov-3.0.0, anyio-3.5.0
collected 69 items / 68 deselected / 1 selected

tests/tasks/test_notebook.py .                                                                                                        [100%]

================================================ 1 passed, 68 deselected, 1 warning in 0.12s ================================================

Related Issue

#694

[edublancas]

thanks for working on this!

at a quick glance, the code looks good.

can you check flake8, I'm seeing this in the CI

./tests/tasks/test_notebook.py:971:1: E302 expected 2 blank lines, found 1

https://github.com/ploomber/ploomber/blob/master/CONTRIBUTING.md#submitting-code

[edublancas]

please show a code example as part of the error message:

perhaps you meant passing a pathlib.Path object like this:

from pathlib import Path
NotebookRunner(Path('value-that-the-user-passed'))

[Zhenye-Na]

please show a code example as part of the error message:

sorry, I dont get the question.

[edublancas]

to be more user-friendly, modify the error message so we tell the user how to fix their code (otherwise they need to figure out that they need to add an import and then enclose their string using Path. it'll make it easier for them to know how to fix it :)

[Zhenye-Na]

Oh I see your point. make sense to me.

Let me update the error message in the next revision

[edublancas]

thanks!

[Zhenye-Na]

thanks for working on this!

at a quick glance, the code looks good.

can you check flake8, I'm seeing this in the CI

./tests/tasks/test_notebook.py:971:1: E302 expected 2 blank lines, found 1

https://github.com/ploomber/ploomber/blob/master/CONTRIBUTING.md#submitting-code

Yes, it seems like I did not run flake8 in the project level. fixing it

[edublancas]

thanks for your contribution!