[SolutionArray] Add array size methods

interfaces/cython/cantera/composite.py

@@ -1,5 +1,6 @@
 # This file is part of Cantera. See License.txt in the top-level directory or
 # at https://cantera.org/license.txt for license and copyright information.
+from __future__ import annotations
 
 from ._cantera import *
 import numpy as np
@@ -654,6 +655,35 @@ def __call__(self, *species):
         return SolutionArray(self._phase[species], states=self._states,
                              extra=self._extra)
 
+    def __len__(self) -> int:
+        return self._shape[0]
+
+    @property
+    def ndim(self) -> int:
+        """The number of dimensions in the SolutionArray.
+
+        .. versionadded:: 3.0
+        """
+        return len(self.shape)
+
+    @property
+    def shape(self) -> tuple[int, ...]:
+        """The shape of the SolutionArray.
+
+        .. versionadded: 3.0
+
+        :return: A tuple of integers with the number of elements in each dimension.
+        """
+        return self._shape
+
+    @property
+    def size(self) -> int:
+        """The number of elements in the SolutionArray.
+
+        .. versionadded: 3.0
+        """
+        return np.prod(self.shape)
+
     def append(self, state=None, normalize=True, **kwargs):
         """
         Append an element to the array with the specified state. Elements can

interfaces/cython/cantera/test/test_composite.py

@@ -240,6 +240,10 @@ def test_append_state(self):
         self.assertEqual(states[0].T, gas.T)
         self.assertEqual(states[0].P, gas.P)
         self.assertArrayNear(states[0].X, gas.X)
+        self.assertEqual(len(states), 1)
+        self.assertEqual(states.shape, (1,))
+        self.assertEqual(states.ndim, 1)
+        self.assertEqual(states.size, 1)
 
     def test_append_no_norm_data(self):
         gas = ct.Solution("h2o2.yaml")