[Exp PyROOT] Add test for pythonized getters of TGraph family

bindings/pyroot_experimental/PyROOT/test/CMakeLists.txt

@@ -27,6 +27,9 @@ ROOT_ADD_PYUNITTEST(pyroot_pyz_ttree_branch ttree_branch.py
 # TH1 and subclasses pythonizations
 ROOT_ADD_PYUNITTEST(pyroot_pyz_th1_operators th1_operators.py)
 
+# TGraph, TGraph2D and error subclasses pythonizations
+ROOT_ADD_PYUNITTEST(pyroot_pyz_tgraph_getters tgraph_getters.py)
+
 # TCollection and subclasses pythonizations
 ROOT_ADD_PYUNITTEST(pyroot_pyz_tcollection_len tcollection_len.py)
 ROOT_ADD_PYUNITTEST(pyroot_pyz_tcollection_listmethods tcollection_listmethods.py)

bindings/pyroot_experimental/PyROOT/test/tgraph_getters.py

+import unittest
+import array
+
+import ROOT
+
+
+class TGraphGetters(unittest.TestCase):
+    """
+    Test for the pythonization of TGraph, TGraph2D and their error
+    subclasses, in particular of their X,Y,Z coordinates and errors
+    getters, which sets the size of the returned buffers.
+    """
+
+    # Tests
+    def test_graph(self):
+        N = 5
+        xval, yval = 1, 2
+
+        ax = array.array('d', map(lambda x: x*xval, range(N)))
+        ay = array.array('d', map(lambda x: x*yval, range(N)))
+
+        g = ROOT.TGraph(N, ax, ay)
+
+        # x and y are buffers of doubles
+        x = g.GetX()
+        y = g.GetY()
+
+        # We can get the size of the buffers
+        self.assertEqual(len(x), N)
+        self.assertEqual(len(y), N)
+
+        # The buffers are iterable
+        self.assertEqual(list(x), list(ax))
+        self.assertEqual(list(y), list(ay))
+
+    def test_graph2derrors(self):
+        N = 5
+        xval, yval, zval = 1, 2, 3
+        xerrval, yerrval, zerrval = 0.1, 0.2, 0.3
+
+        ax = array.array('d', map(lambda x: x*xval, range(N)))
+        ay = array.array('d', map(lambda x: x*yval, range(N)))
+        az = array.array('d', map(lambda x: x*zval, range(N)))
+        aex = array.array('d', map(lambda x: x*xerrval, range(N)))
+        aey = array.array('d', map(lambda x: x*yerrval, range(N)))
+        aez = array.array('d', map(lambda x: x*zerrval, range(N)))
+
+        g = ROOT.TGraph2DErrors(N, ax, ay, az, aex, aey, aez)
+
+        # x, y, z, ex, ey and ez are buffers of doubles
+        x = g.GetX()
+        y = g.GetY()
+        z = g.GetZ()
+        ex = g.GetEX()
+        ey = g.GetEY()
+        ez = g.GetEZ()
+
+        # We can get the size of the buffers
+        self.assertEqual(len(x), N)
+        self.assertEqual(len(y), N)
+        self.assertEqual(len(z), N)
+        self.assertEqual(len(ex), N)
+        self.assertEqual(len(ey), N)
+        self.assertEqual(len(ez), N)
+
+        # The buffers are iterable
+        self.assertEqual(list(x), list(ax))
+        self.assertEqual(list(y), list(ay))
+        self.assertEqual(list(z), list(az))
+        self.assertEqual(list(ex), list(aex))
+        self.assertEqual(list(ey), list(aey))
+        self.assertEqual(list(ez), list(aez))
+
+
+if __name__ == '__main__':
+    unittest.main()