[Review Needed]Pytest Style core/test_segmentgroup.py

testsuite/MDAnalysisTests/core/test_segmentgroup.py

@@ -22,66 +22,74 @@
 from __future__ import absolute_import
 
 from numpy.testing import (
-    assert_,
     assert_equal,
 )
 import pytest
-from unittest import TestCase
 
 import MDAnalysis as mda
 
 from MDAnalysisTests.datafiles import PSF, DCD
 
 
-class TestSegmentGroup(TestCase):
-    # Legacy tests from before 363
-    def setUp(self):
-        """Set up the standard AdK system in implicit solvent."""
-        self.universe = mda.Universe(PSF, DCD)
-        self.g = self.universe.atoms.segments
+# Legacy tests from before 363
+@pytest.fixture()
+def universe():
+    return mda.Universe(PSF, DCD)
 
-    def test_newSegmentGroup(self):
-        """test that slicing a SegmentGroup returns a new SegmentGroup (Issue 135)"""
-        g = self.universe.atoms.segments
-        newg = g[:]
-        assert_(isinstance(newg, mda.core.groups.SegmentGroup))
-        assert_equal(len(newg), len(g))
 
-    def test_n_atoms(self):
-        assert_equal(self.g.n_atoms, 3341)
+@pytest.fixture()
+def g(universe):
+    return universe.atoms.segments
 
-    def test_n_residues(self):
-        assert_equal(self.g.n_residues, 214)
 
-    def test_resids_dim(self):
-        assert_equal(len(self.g.resids), len(self.g))
-        for seg, resids in zip(self.g, self.g.resids):
-            assert_(len(resids) == len(seg.residues))
-            assert_equal(seg.residues.resids, resids)
+def test_newSegmentGroup(universe):
+    """test that slicing a SegmentGroup returns a new SegmentGroup (Issue 135)"""
+    g = universe.atoms.segments
+    newg = g[:]
+    assert isinstance(newg, mda.core.groups.SegmentGroup)
+    assert_equal(len(newg), len(g))
 
-    def test_resnums_dim(self):
-        assert_equal(len(self.g.resnums), len(self.g))
-        for seg, resnums in zip(self.g, self.g.resnums):
-            assert_(len(resnums) == len(seg.residues))
-            assert_equal(seg.residues.resnums, resnums)
 
-    def test_segids_dim(self):
-        assert_equal(len(self.g.segids), len(self.g))
+def test_n_atoms(g):
+    assert_equal(g.n_atoms, 3341)
 
-    def test_set_segids(self):
-        s = self.universe.select_atoms('all').segments
-        s.segids = 'ADK'
-        assert_equal(self.universe.segments.segids, ['ADK'],
-                     err_msg="failed to set_segid on segments")
 
-    def test_set_segid_updates_self(self):
-        g = self.universe.select_atoms("resid 10:18").segments
-        g.segids = 'ADK'
-        assert_equal(g.segids, ['ADK'],
-                     err_msg="old selection was not changed in place after set_segid")
+def test_n_residues(g):
+    assert_equal(g.n_residues, 214)
 
-    def test_atom_order(self):
-        assert_equal(self.universe.segments.atoms.indices,
-                     sorted(self.universe.segments.atoms.indices))
 
+def test_resids_dim(g):
+    assert_equal(len(g.resids), len(g))
+    for seg, resids in zip(g, g.resids):
+        assert len(resids) == len(seg.residues)
+        assert_equal(seg.residues.resids, resids)
 
+
+def test_resnums_dim(g):
+    assert_equal(len(g.resnums), len(g))
+    for seg, resnums in zip(g, g.resnums):
+        assert len(resnums) == len(seg.residues)
+        assert_equal(seg.residues.resnums, resnums)
+
+
+def test_segids_dim(g):
+    assert_equal(len(g.segids), len(g))
+
+
+def test_set_segids(universe):
+    s = universe.select_atoms('all').segments
+    s.segids = 'ADK'
+    assert_equal(universe.segments.segids, ['ADK'],
+                 err_msg="failed to set_segid on segments")
+
+
+def test_set_segid_updates_(universe):
+    g = universe.select_atoms("resid 10:18").segments
+    g.segids = 'ADK'
+    assert_equal(g.segids, ['ADK'],
+                 err_msg="old selection was not changed in place after set_segid")
+
+
+def test_atom_order(universe):
+    assert_equal(universe.segments.atoms.indices,
+                 sorted(universe.segments.atoms.indices))