Bug fix #3593 - approx repr in a 0-d numpy array

[marcelotrevisani]

If the user pass as a expected value a numpy array created like
numpy.array(5); it will creates an array with one element without shape,
when used with approx it will raise an error
'TypeError: iteration over a 0-d array'

Thanks for submitting a PR, your contribution is really appreciated!

Here's a quick checklist that should be present in PRs (you can delete this text from the final description, this is
just a guideline):

• Create a new changelog file in the changelog folder, with a name like <ISSUE NUMBER>.<TYPE>.rst. See changelog/README.rst for details.
• Target the master branch for bug fixes, documentation updates and trivial changes.
• Target the features branch for new features and removals/deprecations.
• Include documentation when adding new features.
• Include new tests or update existing tests when applicable.

Unless your change is trivial or a small documentation fix (e.g., a typo or reword of a small section) please:

• Add yourself to AUTHORS in alphabetical order;

[marcelotrevisani]

@nicoddemus please review

[marcelotrevisani]

@nicoddemus
The black is failing, I ran that in my machine and it returned:

reformatted /home/trevisani/Projetos/pytest/doc/en/example/nonpython/conftest.py
error: cannot format /home/trevisani/Projetos/pytest/doc/en/example/py2py3/test_py2.py: cannot use --safe with this file; failed to parse source file with Python 3.6's builtin AST. Re-run with --fast or stop using deprecated Python 2 syntax. AST error message: invalid syntax (<unknown>, line 5)

So, how do I have to proceed in this case?

[RonnyPfannschmidt]

use pre-commit - it has the excludes defined

[marcelotrevisani]

@RonnyPfannschmidt it gave me the same thing...

pre-commit run --all-files
black....................................................................Failed
hookid: black

Files were modified by this hook.

blacken-docs.............................................................Passed
Trim Trailing Whitespace.................................................Passed
Fix End of Files.........................................................Passed
Check Yaml...............................................................Passed
Debug Statements (Python)................................................Passed
Flake8...................................................................Passed
pyupgrade................................................................Passed
rst......................................................................Passed

[RonnyPfannschmidt]

@marcelotrevisani but it should also leave the changed files in the worktree to review/commit/amend

[marcelotrevisani]

Are this errors related to #3614 ?

[RonnyPfannschmidt]

@marcelotrevisani we pin the black version to get consistency across the codebase, i beleive the difference you see is due to black version differences

[RonnyPfannschmidt]

also yes, #3614 is related

[marcelotrevisani]

So, do I have to run black in my branch and commit the changes?

[coveralls]

Coverage increased (+0.02%) to 92.648% when pulling 0030ceb on marcelotrevisani:bug-3593-pytest-approx into 42b3125 on pytest-dev:master.

[marcelotrevisani]

So, the CI is failing and I think it's related to the issue #2111

>       assert str(approx(np_array)) == "approx([5.0 ± 5.0e-06])"
E       AssertionError: assert 'approx([5.0 +- 5.0e-06])' == 'approx([5.0 \xc2\xb1 5.0e-06])'
E         - approx([5.0 +- 5.0e-06])
E         ?             ^^
E         + approx([5.0 \xc2\xb1 5.0e-06])
E         ?             ^^^^^^^^
testing\python\approx.py:339: AssertionError

[RonnyPfannschmidt]

test_repr_string sorts that out using a variable and formatting, i propose moving the str tests over there

[marcelotrevisani]

@RonnyPfannschmidt got it, I will change that later. However this is still failing for py27-numpy in the CI, with the same error. I will take a look after work, but do you have a hint for this case?

[RonnyPfannschmidt]

@marcelotrevisani not off hand, im unfamiliar with approx (i have never needed/used it myself)

[RonnyPfannschmidt]

great work, thanks, i will merge this, then investigate the fallout it causes fore the black upgrade by @asottile