Update API defs

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/tensorflow/python/ops/string_ops.py b/tensorflow/python/ops/string_ops.py
index 961e63d04e..0280c89c10 100644
--- a/tensorflow/python/ops/string_ops.py
+++ b/tensorflow/python/ops/string_ops.py
@@ -93,6 +93,45 @@ def string_split(source, delimiter=" ", skip_empty=True):  # pylint: disable=inv
 
 @tf_export("strings.split")
 def string_split_v2(source, sep=None, maxsplit=-1):
+  """Split elements of `source` based on `sep` into a `SparseTensor`.
+
+  Let N be the size of source (typically N will be the batch size). Split each
+  element of `source` based on `sep` and return a `SparseTensor`
+  containing the split tokens. Empty tokens are ignored.
+
+  For example, N = 2, source[0] is 'hello world' and source[1] is 'a b c',
+  then the output will be
+
+  st.indices = [0, 0;
+                0, 1;
+                1, 0;
+                1, 1;
+                1, 2]
+  st.shape = [2, 3]
+  st.values = ['hello', 'world', 'a', 'b', 'c']
+
+  If `sep` is given, consecutive delimiters are not grouped together and are
+  deemed to delimit empty strings. For example, source of `"1<>2<><>3"` and
+  sep of `"<>"` returns `["1", "2", "", "3"]`. If `sep` is None or an empty
+  string, consecutive whitespace are regarded as a single separator, and the
+  result will contain no empty strings at the startor end if the string has
+  leading or trailing whitespace.
+
+  Note that the above mentioned behavior matches python's str.split.
+
+  Args:
+    source: `1-D` string `Tensor`, the strings to split.
+    sep: `0-D` string `Tensor`, the delimiter character.
+    maxsplit: An `int`. If `maxsplit > 0`, limit of the split of the result.
+
+  Raises:
+    ValueError: If sep is not a string.
+
+  Returns:
+    A `SparseTensor` of rank `2`, the strings split according to the delimiter.
+    The first column of the indices corresponds to the row in `source` and the
+    second column corresponds to the index of the split component in this row.
+  """
   if sep is None:
     sep = ''
   sep = ops.convert_to_tensor(sep, dtype=dtypes.string)