Bug fix #3593 - approx method in a single element of numpy array

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'

AUTHORS

@@ -126,6 +126,7 @@ Maik Figura
 Mandeep Bhutani
 Manuel Krebber
 Marc Schlaich
+Marcelo Duarte Trevisani
 Marcin Bachry
 Mark Abramowitz
 Markus Unterwaditzer

changelog/3593.bugfix.rst

@@ -0,0 +1,5 @@
+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 for the `repr`
+'TypeError: iteration over a 0-d array'. With this PR pytest will iterate
+properly in the numpy array even with 0 dimension.

src/_pytest/python_api.py

@@ -86,9 +86,11 @@ def __repr__(self):
  # shape of the array...
  import numpy as np
 
- return "approx({!r})".format(
- list(self._approx_scalar(x) for x in np.asarray(self.expected))
- )
+ list_scalars = []
+ for x in np.ndindex(self.expected.shape):
+ list_scalars.append(self._approx_scalar(np.asscalar(self.expected[x])))
+
+ return "approx({!r})".format(list_scalars)
 
  if sys.version_info[0] == 2:
  __cmp__ = _cmp_raises_type_error

testing/python/approx.py

@@ -27,8 +27,11 @@ def report_failure(self, out, test, example, got):
 
 class TestApprox(object):
 
- def test_repr_string(self):
- plus_minus = u"\u00b1" if sys.version_info[0] > 2 else u"+-"
+ @pytest.fixture
+ def plus_minus(self):
+ return u"\u00b1" if sys.version_info[0] > 2 else u"+-"
+
+ def test_repr_string(self, plus_minus):
  tol1, tol2, infr = "1.0e-06", "2.0e-06", "inf"
  assert repr(approx(1.0)) == "1.0 {pm} {tol1}".format(pm=plus_minus, tol1=tol1)
  assert (
@@ -61,6 +64,18 @@ def test_repr_string(self):
  ),
  )
 
+ def test_repr_0d_array(self, plus_minus):
+ np = pytest.importorskip("numpy")
+ np_array = np.array(5.)
+ assert approx(np_array) == 5.0
+ string_expected = "approx([5.0 {} 5.0e-06])".format(plus_minus)
+
+ assert repr(approx(np_array)) == string_expected
+
+ np_array = np.array([5.])
+ assert approx(np_array) == 5.0
+ assert repr(approx(np_array)) == string_expected
+
  def test_operator_overloading(self):
  assert 1 == approx(1, rel=1e-6, abs=1e-12)
  assert not (1 != approx(1, rel=1e-6, abs=1e-12))