Add get_seed() and test/doc (#40)

Author: lmas

README.md

@@ -97,6 +97,14 @@ For more advanced examples, see the files in the [tests](./tests/) and [examples
 
     random_seed()
 
+**get_seed()**
+
+    Return the value used to seed the initial state.
+    :return: seed as integer
+
+    >>> get_seed()
+    3
+
 **opensimplex.noise2(x, y)**
 
     Generate 2D OpenSimplex noise from X,Y coordinates.

opensimplex/api.py

@@ -33,6 +33,16 @@ def random_seed() -> None:
     seed(time.time_ns())
 
 
+def get_seed() -> int:
+    """
+    Return the value used to seed the initial state.
+    :return: seed as integer
+
+    >>> get_seed()
+    3
+    """
+    return _default.get_seed()
+
 def noise2(x: float, y: float) -> float:
     """
     Generate 2D OpenSimplex noise from X,Y coordinates.
@@ -143,6 +153,10 @@ def noise4array(x: np.ndarray, y: np.ndarray, z: np.ndarray, w: np.ndarray) -> n
 class OpenSimplex(object):
     def __init__(self, seed: int) -> None:
         self._perm, self._perm_grad_index3 = _init(seed)
+        self._seed = seed
+
+    def get_seed(self) -> int:
+        return self._seed
 
     def noise2(self, x: float, y: float) -> float:
         return _noise2(x, y, self._perm)

tests/test_opensimplex.py

@@ -26,6 +26,11 @@ def test_seeds(self):
             if n != row[1]:
                 self.fail("got %s, expected %s (using seed %s)" % (n, row[1], row[0]))
 
+        got = simplex.get_seed()
+        want = test_seeds[-1][0]
+        if got != want:
+            self.fail("got %s, expected %s" % (got, want))
+
     def load_samples(self):
         for line in gzip.open("tests/samples.json.gz"):
             # Python3: need to decode the line as it's a bytes object and json
@@ -53,7 +58,7 @@ def test_samples(self):
                 expected = s[4]
                 actual = simplex.noise4(s[0], s[1], s[2], s[3])
             else:
-                self.fail("Unexpected sample size: " + str(len(s)))
+                self.fail("unexpected sample size: " + str(len(s)))
             self.assertEqual(expected, actual)
 
     def test_arrays(self):