BUG: Fixes #5524 and adds test

argpartition does not fail anymore on non-ndarray array-likes.
Fix as implemented by @maniteja123.

2 files changed, 15 insertions, 1 deletions

diff --git a/numpy/core/fromnumeric.py b/numpy/core/fromnumeric.py
index aef09411a..c518309a0 100644
--- a/numpy/core/fromnumeric.py
+++ b/numpy/core/fromnumeric.py
@@ -691,8 +691,16 @@ def argpartition(a, kth, axis=-1, kind='introselect', order=None):
     >>> x[np.argpartition(x, (1, 3))]
     array([1, 2, 3, 4])
 
+    >>> x = [3, 4, 2, 1]
+    >>> np.array(x)[np.argpartition(x, 3)]
+    array([2, 1, 3, 4])
+
     """
-    return a.argpartition(kth, axis, kind=kind, order=order)
+    try:
+        argpartition = a.argpartition
+    except AttributeError:
+        return _wrapit(a, 'argpartition',kth, axis, kind, order)
+    return argpartition(kth, axis, kind=kind, order=order)
 
 
 def sort(a, axis=-1, kind='quicksort', order=None):
diff --git a/numpy/core/tests/test_multiarray.py b/numpy/core/tests/test_multiarray.py
index b0d677052..164c90cee 100644
--- a/numpy/core/tests/test_multiarray.py
+++ b/numpy/core/tests/test_multiarray.py
@@ -1748,6 +1748,12 @@ class TestMethods(TestCase):
                assert_array_equal(np.partition(d, kth)[kth], tgt,
                                   err_msg="data: %r\n kth: %r" % (d, kth))
 
+    def test_argpartition_gh5524(self):
+        #  A test for functionality of argpartition on lists.
+        d = [6,7,3,2,9,0]
+        p = np.argpartition(d,1)
+        self.assert_partitioned(np.array(d)[p],[1])
+
     def test_flatten(self):
         x0 = np.array([[1, 2, 3], [4, 5, 6]], np.int32)
         x1 = np.array([[[1, 2], [3, 4]], [[5, 6], [7, 8]]], np.int32)