Separate dependencies and lightweight test env for Python

tests/python/test_plotting.py

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+# -*- coding: utf-8 -*-
+import numpy as np
+import xgboost as xgb
+import unittest
+
+import matplotlib
+from matplotlib.axes import Axes
+from graphviz import Digraph
+
+matplotlib.use('Agg')
+
+dpath = 'demo/data/'
+rng = np.random.RandomState(1994)
+
+class TestPlotting(unittest.TestCase):
+    def test_plotting(self):
+        bst2 = xgb.Booster(model_file='xgb.model')
+
+        ax = xgb.plot_importance(bst2)
+        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',
+                                 title='t', xlabel='x', ylabel='y')
+        assert isinstance(ax, Axes)
+        assert ax.get_title() == 't'
+        assert ax.get_xlabel() == 'x'
+        assert ax.get_ylabel() == 'y'
+        assert len(ax.patches) == 4
+        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'],
+                                 title=None, xlabel=None, ylabel=None)
+        assert isinstance(ax, Axes)
+        assert ax.get_title() == ''
+        assert ax.get_xlabel() == ''
+        assert ax.get_ylabel() == ''
+        assert len(ax.patches) == 4
+        assert ax.patches[0].get_facecolor() == (1.0, 0, 0, 1.0)  # red
+        assert ax.patches[1].get_facecolor() == (1.0, 0, 0, 1.0)  # red
+        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)
+        assert isinstance(g, Digraph)
+
+        ax = xgb.plot_tree(bst2, num_trees=0)
+        assert isinstance(ax, Axes)
+
+    def test_importance_plot_lim(self):
+        np.random.seed(1)
+        dm = xgb.DMatrix(np.random.randn(100, 100), label=[0, 1] * 50)
+        bst = xgb.train({}, dm)
+        assert len(bst.get_fscore()) == 71
+        ax = xgb.plot_importance(bst)
+        assert ax.get_xlim() == (0., 11.)
+        assert ax.get_ylim() == (-1., 71.)
+
+        ax = xgb.plot_importance(bst, xlim=(0, 5), ylim=(10, 71))
+        assert ax.get_xlim() == (0., 5.)
+        assert ax.get_ylim() == (10., 71.)