[Review Needed]Pytest Style topology/test_guessers.py

testsuite/MDAnalysisTests/topology/test_guessers.py

@@ -22,12 +22,7 @@
 from __future__ import absolute_import
 
 import pytest
-from numpy.testing import (
-    assert_,
-    assert_array_equal,
-    assert_equal,
-    assert_warns,
-)
+from numpy.testing import assert_equal
 import numpy as np
 
 from MDAnalysis.topology import guessers
@@ -36,29 +31,28 @@
 from MDAnalysisTests import make_Universe
 from MDAnalysisTests.core.test_fragments import make_starshape
 
+
 class TestGuessMasses(object):
     def test_guess_masses(self):
         out = guessers.guess_masses(['C', 'C', 'H'])
-
-        assert_(isinstance(out, np.ndarray))
-        assert_array_equal(out,
-                           np.array([12.011, 12.011, 1.008]))
+
+        assert isinstance(out, np.ndarray)
+        assert_equal(out, np.array([12.011, 12.011, 1.008]))
 
     def test_guess_masses_warn(self):
-        assert_warns(UserWarning, guessers.guess_masses, ['X'])
+        with pytest.warns(UserWarning):
+            guessers.guess_masses(['X'])
 
     def test_guess_masses_miss(self):
         out = guessers.guess_masses(['X', 'Z'])
-        assert_array_equal(out, np.array([0.0, 0.0]))
+        assert_equal(out, np.array([0.0, 0.0]))
 
-    def test_get_atom_mass(self):
-        assert_(guessers.get_atom_mass('H') == 1.008)
-
-    def test_get_atom_mass_miss(self):
-        assert_(guessers.get_atom_mass('XYZ') == 0.0)
+    @pytest.mark.parametrize('element, value', (('H', 1.008), ('XYZ', 0.0), ))
+    def test_get_atom_mass(self, element, value):
+        assert guessers.get_atom_mass(element) == value
 
     def test_guess_atom_mass(self):
-        assert_(guessers.guess_atom_mass('1H') == 1.008)
+        assert guessers.guess_atom_mass('1H') == 1.008
 
 
 class TestGuessTypes(object):
@@ -68,32 +62,34 @@ class TestGuessTypes(object):
     def test_guess_types(self):
         out = guessers.guess_types(['MG2+', 'C12'])
 
-        assert_(isinstance(out, np.ndarray))
-        assert_array_equal(out, np.array(['MG', 'C'], dtype=object))
+        assert isinstance(out, np.ndarray)
+        assert_equal(out, np.array(['MG', 'C'], dtype=object))
 
     def test_guess_atom_element(self):
-        assert_(guessers.guess_atom_element('MG2+') == 'MG')
+        assert guessers.guess_atom_element('MG2+') == 'MG'
 
     def test_guess_atom_element_empty(self):
-        assert_(guessers.guess_atom_element('') == '')
+        assert guessers.guess_atom_element('') == ''
 
     def test_guess_atom_element_singledigit(self):
-        assert_(guessers.guess_atom_element('1') == '1')
+        assert guessers.guess_atom_element('1') == '1'
 
     def test_guess_atom_element_1H(self):
-        assert_(guessers.guess_atom_element('1H') == 'H')
-        assert_(guessers.guess_atom_element('2H') == 'H')
+        assert guessers.guess_atom_element('1H') == 'H'
+        assert guessers.guess_atom_element('2H') == 'H'
+
 
 def test_guess_charge():
     # this always returns 0.0
-    assert_(guessers.guess_atom_charge('this') == 0.0)
+    assert guessers.guess_atom_charge('this') == 0.0
+
 
 def test_guess_bonds_Error():
     u = make_Universe(trajectory=True)
     with pytest.raises(ValueError):
-        guessers.guess_bonds( u.atoms[:4],
-                u.atoms.positions[:5])
-    
+        guessers.guess_bonds(u.atoms[:4], u.atoms.positions[:5])
+
+
 def test_guess_impropers():
     u = make_starshape()