Fix plotting test. (#6040)

Previously the test loads a model generated by `test_basic.py`, now we generate
the model explicitly.

* Cleanup saved files for basic tests.

tests/python/test_basic.py

@@ -110,13 +110,16 @@ class TestBasic(unittest.TestCase):
         # error must be smaller than 10%
         assert err < 0.1
 
+        with tempfile.TemporaryDirectory() as tmpdir:
+            dtest_path = os.path.join(tmpdir, 'dtest.buffer')
+            model_path = os.path.join(tmpdir, 'xgb.model')
             # save dmatrix into binary buffer
-        dtest.save_binary('dtest.buffer')
+            dtest.save_binary(dtest_path)
             # save model
-        bst.save_model('xgb.model')
+            bst.save_model(model_path)
             # load model and data in
-        bst2 = xgb.Booster(model_file='xgb.model')
-        dtest2 = xgb.DMatrix('dtest.buffer')
+            bst2 = xgb.Booster(model_file=model_path)
+            dtest2 = xgb.DMatrix(dtest_path)
             preds2 = bst2.predict(dtest2)
             # assert they are the same
             assert np.sum(np.abs(preds2 - preds)) == 0

tests/python/test_basic_models.py

@@ -6,6 +6,7 @@ import json
 import testing as tm
 import pytest
 import locale
+import tempfile
 
 dpath = 'demo/data/'
 dtrain = xgb.DMatrix(dpath + 'agaricus.txt.train')
@@ -60,15 +61,20 @@ class TestModels(unittest.TestCase):
         # error must be smaller than 10%
         assert err < 0.1
 
+        with tempfile.TemporaryDirectory() as tmpdir:
+            dtest_path = os.path.join(tmpdir, 'dtest.dmatrix')
+            model_path = os.path.join(tmpdir, 'xgboost.model.dart')
             # save dmatrix into binary buffer
-        dtest.save_binary('dtest.buffer')
-        model_path = 'xgb.model.dart'
+            dtest.save_binary(dtest_path)
+            model_path = model_path
             # save model
             bst.save_model(model_path)
             # load model and data in
-        bst2 = xgb.Booster(params=param, model_file='xgb.model.dart')
-        dtest2 = xgb.DMatrix('dtest.buffer')
+            bst2 = xgb.Booster(params=param, model_file=model_path)
+            dtest2 = xgb.DMatrix(dtest_path)
+
         preds2 = bst2.predict(dtest2, ntree_limit=num_round)
+
         # assert they are the same
         assert np.sum(np.abs(preds2 - preds)) == 0
 
@@ -103,7 +109,6 @@ class TestModels(unittest.TestCase):
         for ii in range(len(preds_list)):
             for jj in range(ii + 1, len(preds_list)):
                 assert np.sum(np.abs(preds_list[ii] - preds_list[jj])) > 0
-        os.remove(model_path)
 
     def run_eta_decay(self, tree_method):
         watchlist = [(dtest, 'eval'), (dtrain, 'train')]

tests/python/test_plotting.py

@@ -14,27 +14,27 @@ try:
 except ImportError:
     pass
 
+pytestmark = pytest.mark.skipif(**tm.no_multiple(tm.no_matplotlib(),
+                                                 tm.no_graphviz()))
 
-pytestmark = pytest.mark.skipif(**tm.no_multiple(tm.no_matplotlib(), tm.no_graphviz()))
-
-
-dpath = 'demo/data/'
-rng = np.random.RandomState(1994)
+dpath = 'demo/data/agaricus.txt.train'
 
 
 class TestPlotting(unittest.TestCase):
-
     def test_plotting(self):
-        bst2 = xgb.Booster(model_file='xgb.model')
+        m = xgb.DMatrix(dpath)
+        booster = xgb.train({'max_depth': 2, 'eta': 1,
+                             'objective': 'binary:logistic'}, m,
+                            num_boost_round=2)
 
-        ax = xgb.plot_importance(bst2)
+        ax = xgb.plot_importance(booster)
         assert isinstance(ax, Axes)
         assert ax.get_title() == 'Feature importance'
         assert ax.get_xlabel() == 'F score'
         assert ax.get_ylabel() == 'Features'
         assert len(ax.patches) == 4
 
-        ax = xgb.plot_importance(bst2, color='r',
+        ax = xgb.plot_importance(booster, color='r',
                                  title='t', xlabel='x', ylabel='y')
         assert isinstance(ax, Axes)
         assert ax.get_title() == 't'
@@ -44,7 +44,7 @@ class TestPlotting(unittest.TestCase):
         for p in ax.patches:
             assert p.get_facecolor() == (1.0, 0, 0, 1.0)  # red
 
-        ax = xgb.plot_importance(bst2, color=['r', 'r', 'b', 'b'],
+        ax = xgb.plot_importance(booster, color=['r', 'r', 'b', 'b'],
                                  title=None, xlabel=None, ylabel=None)
         assert isinstance(ax, Axes)
         assert ax.get_title() == ''
@@ -56,10 +56,10 @@ class TestPlotting(unittest.TestCase):
         assert ax.patches[2].get_facecolor() == (0, 0, 1.0, 1.0)  # blue
         assert ax.patches[3].get_facecolor() == (0, 0, 1.0, 1.0)  # blue
 
-        g = xgb.to_graphviz(bst2, num_trees=0)
+        g = xgb.to_graphviz(booster, num_trees=0)
         assert isinstance(g, Source)
 
-        ax = xgb.plot_tree(bst2, num_trees=0)
+        ax = xgb.plot_tree(booster, num_trees=0)
         assert isinstance(ax, Axes)
 
     def test_importance_plot_lim(self):