add sampler

doc/fluid/api/io.rst

@@ -7,6 +7,9 @@ fluid.io
 
     io/batch.rst
     io/BatchSampler.rst
+    io/Sampler.rst
+    io/SequenceSampler.rst
+    io/RandomSampler.rst
     io/buffered.rst
     io/cache.rst
     io/chain.rst

doc/fluid/api/io/RandomSampler.rst

+.. _api_io_RandomSampler:
+
+RandomSampler
+-------------------------------
+..  autoclass:: paddle.fluid.io.RandomSampler
+    :members:
+    :inherited-members:
+    :noindex:
+
+

doc/fluid/api/io/Sampler.rst

+.. _api_io_Sampler:
+
+Sampler
+-------------------------------
+..  autoclass:: paddle.fluid.io.Sampler
+    :members:
+    :inherited-members:
+    :noindex:
+
+

doc/fluid/api/io/SequenceSampler.rst

+.. _api_io_SequenceSampler:
+
+SequenceSampler
+-------------------------------
+..  autoclass:: paddle.fluid.io.SequenceSampler
+    :members:
+    :inherited-members:
+    :noindex:
+
+