Skip test that uses np.nanmedian for older versions of Numpy, and do …

…other skip-related cleanup.

spectral_cube/tests/test_spectral_cube.py

@@ -1,12 +1,13 @@
-import pytest
 import operator
 import itertools
 import warnings
 import mmap
+from distutils.version import StrictVersion, LooseVersion
 
 # needed to test for warnings later
 warnings.simplefilter('always', UserWarning)
 
+import pytest
 
 from astropy.io import fits
 from astropy import units as u
@@ -23,23 +24,20 @@
 from . import path
 from .helpers import assert_allclose, assert_array_equal
 
-from distutils.version import StrictVersion
 
 try:
     import yt
-    ytOK = True
-    yt_version = (StrictVersion(yt.__version__[:-4])
-                  if 'dev' in yt.__version__ else
-                  StrictVersion(yt.__version__))
+    YT_INSTALLED = True
+    YT_LT_301 = LooseVersion(yt.__version__) < LooseVersion('3.0.1')
 except ImportError:
-    yt_version = StrictVersion('0.0.0')
-    ytOK = False
+    YT_INSTALLED = False
+    YT_LT_301 = False
 
 try:
     import bottleneck
-    bottleneckOK = True
+    BOTTLENECK_INSTALLED = True
 except ImportError:
-    bottleneckOK = False
+    BOTTLENECK_INSTALLED = False
 
 try:
     from radio_beam import Beam
@@ -48,6 +46,9 @@
     RADIO_BEAM_INSTALLED = False
 
 
+NUMPY_LT_19 = LooseVersion(np.__version__) < LooseVersion('1.9.0')
+
+
 def cube_and_raw(filename):
     p = path(filename)
 
@@ -444,6 +445,7 @@ def test_median(self, iterate_rays):
         assert not np.any(np.isnan(scmed.value))
         assert scmed.unit == self.c.unit
 
+    @pytest.mark.skipif('NUMPY_LT_19')
     def test_bad_median_apply(self):
         # this is a test for manually-applied numpy medians, which are different
         # from the cube.median method that does "the right thing"
@@ -563,7 +565,7 @@ def test_repr_withunit(self):
         """.strip()
 
 
-@pytest.mark.skipif(not ytOK, reason='Could not import yt')
+@pytest.mark.skipif('not YT_INSTALLED')
 class TestYt():
     def setup_method(self, method):
         self.cube = SpectralCube.read(path('adv.fits'))
@@ -602,7 +604,7 @@ def test_yt(self):
         ds2.quan(1.0,unit2)
         ds3.quan(1.0,unit3)
 
-    @pytest.mark.skipif(yt_version < StrictVersion('3.0.1'), reason='yt 3.0 has a FITS-related bug')
+    @pytest.mark.skipif('YT_LT_301')
     def test_yt_fluxcompare(self):
         # Now check that we can compute quantities of the flux
         # and that they are equal
@@ -749,7 +751,7 @@ def test_preserve_spectral_unit():
     assert new_cube.spectral_axis.unit is u.GHz
 
 
-@pytest.mark.skipif(not bottleneckOK, reason='Bottleneck could not be imported')
+@pytest.mark.skipif('not BOTTLENECK_INSTALLED')
 def test_endians():
     """
     Test that the endianness checking returns something in Native form
@@ -974,7 +976,7 @@ def test_preserve_bunit():
     assert cube.unit == u.Jy
     assert cube.header['BUNIT'] == 'Jy'
 
-@pytest.mark.skipif("not RADIO_BEAM_INSTALLED")
+@pytest.mark.skipif('not RADIO_BEAM_INSTALLED')
 def test_preserve_beam():
 
     cube, data = cube_and_raw('advs.fits')
@@ -983,7 +985,7 @@ def test_preserve_beam():
 
     assert cube.beam == beam
 
-@pytest.mark.skipif("not RADIO_BEAM_INSTALLED")
+@pytest.mark.skipif('not RADIO_BEAM_INSTALLED')
 def test_append_beam_to_hdr():
 
     cube, data = cube_and_raw('advs.fits')
@@ -1034,7 +1036,7 @@ def test_jybeam_whitespace():
         np.testing.assert_almost_equal(cube.beam.sr.value,
                                        (((1*u.arcsec/np.sqrt(8*np.log(2)))**2).to(u.sr)*2*np.pi).value)
 
-@pytest.mark.skipif("not RADIO_BEAM_INSTALLED")
+@pytest.mark.skipif('not RADIO_BEAM_INSTALLED')
 def test_beam_proj_meta():
 
     cube, data = cube_and_raw('advs.fits')