Add docstring

python/pylibraft/pylibraft/cluster/kmeans.pyx

@@ -203,11 +203,24 @@ def compute_new_centroids(X,
 @auto_sync_handle
 @auto_convert_output
 def init_plus_plus(X, n_clusters=None, seed=None, handle=None, centroids=None):
-    if n_clusters is not None and centroids is not None:
-        msg = ("Parameters 'n_clusters' and 'centroids' are exclusive. Only " +
-               "pass one at a time.")
-        raise RuntimeError(msg)
+    """
+    Compute initial centroids using the "kmeans++" algorithm.
+
+    Parameters
+    ----------
+
+    X : Input CUDA array interface compliant matrix shape (m, k)
+    n_clusters : Number of clusters to select
+    seed : Controls the random sampling of centroids
+    centroids : Optional writable CUDA array interface compliant matrix shape
+                (n_clusters, k). Use instead of passing `n_clusters`.
+    {handle_docstring}
+
+    Examples
+    --------
 
+    >>> import cupy as cp
+    """
     cdef device_resources *h = <device_resources*><size_t>handle.getHandle()
 
     X_cai = cai_wrapper(X)