!1157 dataset: add concat operation for dataset

Merge pull request !1157 from ms_yan/concat_dataset

mindspore/ccsrc/dataset/api/de_pipeline.cc

@@ -53,6 +53,7 @@ static std::unordered_map<uint32_t, pFunction> g_parse_op_func_ = {{kStorage, &D
                                                                    {kRepeat, &DEPipeline::ParseRepeatOp},
                                                                    {kSkip, &DEPipeline::ParseSkipOp},
                                                                    {kZip, &DEPipeline::ParseZipOp},
+                                                                   {kConcat, &DEPipeline::ParseConcatOp},
                                                                    {kRename, &DEPipeline::ParseRenameOp},
                                                                    {kDeviceQueue, &DEPipeline::ParseDeviceQueueOp},
                                                                    {kGenerator, &DEPipeline::ParseGeneratorOp},
@@ -757,6 +758,14 @@ Status DEPipeline::ParseZipOp(const py::dict &args, std::shared_ptr<DatasetOp> *
   return Status::OK();
 }
 
+Status DEPipeline::ParseConcatOp(const py::dict &args, std::shared_ptr<DatasetOp> *ptr) {
+  std::shared_ptr<ConcatOp::Builder> builder = std::make_shared<ConcatOp::Builder>();
+  std::shared_ptr<ConcatOp> op;
+  RETURN_IF_NOT_OK(builder->Build(&op));
+  *ptr = op;
+  return Status::OK();
+}
+
 Status DEPipeline::ParseTFReaderOp(const py::dict &args, std::shared_ptr<DatasetOp> *ptr) {
   // Required arguments
   std::shared_ptr<TFReaderOp::Builder> builder = std::make_shared<TFReaderOp::Builder>();

mindspore/ccsrc/dataset/api/de_pipeline.h

@@ -46,6 +46,7 @@ enum OpName {
   kSkip,
   kTake,
   kZip,
+  kConcat,
   kMap,
   kFilter,
   kDeviceQueue,
@@ -127,6 +128,8 @@ class DEPipeline {
 
   Status ParseZipOp(const py::dict &args, std::shared_ptr<DatasetOp> *ptr);
 
+  Status ParseConcatOp(const py::dict &args, std::shared_ptr<DatasetOp> *ptr);
+
   Status ParseDeviceQueueOp(const py::dict &args, std::shared_ptr<DatasetOp> *ptr);
 
   Status ParseTFReaderOp(const py::dict &args, std::shared_ptr<DatasetOp> *ptr);

mindspore/ccsrc/dataset/api/python_bindings.cc

@@ -476,6 +476,7 @@ PYBIND11_MODULE(_c_dataengine, m) {
     .value("SKIP", OpName::kSkip)
     .value("TAKE", OpName::kTake)
     .value("ZIP", OpName::kZip)
+    .value("CONCAT", OpName::kConcat)
     .value("MAP", OpName::kMap)
     .value("FILTER", OpName::kFilter)
     .value("DEVICEQUEUE", OpName::kDeviceQueue)

mindspore/ccsrc/dataset/core/client.h

@@ -42,6 +42,7 @@
 #include "dataset/engine/datasetops/source/tf_reader_op.h"
 #include "dataset/engine/datasetops/take_op.h"
 #include "dataset/engine/datasetops/zip_op.h"
+#include "dataset/engine/datasetops/concat_op.h"
 #include "dataset/engine/execution_tree.h"
 #include "dataset/util/status.h"
 

mindspore/ccsrc/dataset/engine/datasetops/CMakeLists.txt

@@ -17,6 +17,7 @@ add_library(engine-datasetops OBJECT
     take_op.cc
     shuffle_op.cc
     zip_op.cc
+    concat_op.cc
     filter_op.cc
     )
 

mindspore/ccsrc/dataset/engine/datasetops/concat_op.cc

@@ -0,0 +1,145 @@
+/**
+ * Copyright 2020 Huawei Technologies Co., Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <iomanip>
+#include <utility>
+
+#include "common/utils.h"
+#include "dataset/core/config_manager.h"
+#include "dataset/engine/data_buffer.h"
+#include "dataset/engine/datasetops/concat_op.h"
+#include "dataset/engine/db_connector.h"
+#include "dataset/engine/execution_tree.h"
+
+namespace mindspore {
+namespace dataset {
+// Builder constructor. Creates the builder object.
+ConcatOp::Builder::Builder() {
+  std::shared_ptr<ConfigManager> cfg = GlobalContext::config_manager();
+  builder_op_connector_size_ = cfg->op_connector_size();
+}
+
+// The builder "build" method creates the final object.
+Status ConcatOp::Builder::Build(std::shared_ptr<ConcatOp> *ptr) {
+  *ptr = std::make_shared<ConcatOp>(builder_op_connector_size_);
+  return Status::OK();
+}
+
+// Constructor of the ConcatOp.
+ConcatOp::ConcatOp(int32_t op_connector_size) : PipelineOp(op_connector_size), children_num_(0) {}
+
+// A function that prints info about the Operator
+void ConcatOp::Print(std::ostream &out, bool show_all) const {
+  // Always show the id and name as first line regardless if this is summary or detailed print
+  out << "(" << std::setw(2) << operator_id_ << ") <ConcatOp>:";
+  if (!show_all) {
+    // Call the super class for displaying any common 1-liner info
+    PipelineOp::Print(out, show_all);
+    // Then show any custom derived-internal 1-liner info for this op
+    out << "\n";
+  } else {
+    // Call the super class for displaying any common detailed info
+    PipelineOp::Print(out, show_all);
+    // Then show any custom derived-internal stuff
+    out << "\nDatasets: " << children_num_ << "\n\n";
+  }
+}
+
+// Main entry point for Concat
+Status ConcatOp::operator()() {
+  // The children_num_ parameter needs to be put here
+  children_num_ = static_cast<int32_t>(child_.size());
+
+  TaskManager::FindMe()->Post();
+  std::unique_ptr<DataBuffer> buf;
+  RETURN_IF_NOT_OK(child_[0]->GetNextBuffer(&buf));
+
+  // Obtain columns_name_id_map from child_[0]
+  column_name_id_map_ = child_[0]->column_name_id_map();
+  if (column_name_id_map_.empty()) {
+    RETURN_STATUS_UNEXPECTED("Child column name map cannot be empty!");
+  }
+
+  int eof_count = 0;
+  while (eof_count != children_num_) {
+    for (int i = 0; i < children_num_; i++) {
+      // 1. Throw the eof buffer when meet it
+      if (buf->eof() || buf->eoe()) {
+        RETURN_IF_NOT_OK(child_[i]->GetNextBuffer(&buf));
+      }
+      // 2. Do varification as for column name, column data type and rank of column data
+      RETURN_IF_NOT_OK(Verify(i, buf));
+
+      // 3. Put the data into output_connector
+      while (!buf->eoe() && !buf->eof()) {
+        RETURN_IF_NOT_OK(out_connector_->Add(0, std::move(buf)));
+        RETURN_IF_NOT_OK(child_[i]->GetNextBuffer(&buf));
+      }
+
+      // 4. Throw the eoe buffer when meet it
+      if (buf->eoe() && (!BitTest(op_ctrl_flags_, kDeOpRepeated) || BitTest(op_ctrl_flags_, kDeOpLastRepeat))) {
+        RETURN_IF_NOT_OK(child_[i]->GetNextBuffer(&buf));
+      }
+      // 5. Add eoe buffer after get buffer from all child
+      if (i == (children_num_ - 1)) {
+        auto eoe_buffer = std::make_unique<DataBuffer>(0, DataBuffer::kDeBFlagEOE);
+        RETURN_IF_NOT_OK(out_connector_->Add(0, std::move(eoe_buffer)));
+      }
+      if (buf->eof()) {
+        eof_count++;
+      }
+    }
+  }
+  // 6. Add eof buffer in the end manually
+  MS_LOG(DEBUG) << "Add the eof buffer manualy in the end.";
+  auto eof_buffer = std::make_unique<DataBuffer>(0, DataBuffer::kDeBFlagEOF);
+  RETURN_IF_NOT_OK(out_connector_->Add(0, std::move(eof_buffer)));
+
+  return Status::OK();
+}
+
+Status ConcatOp::Verify(int32_t id, const std::unique_ptr<DataBuffer> &buf) {
+  TensorRow new_row;
+  buf->GetRow(0, &new_row);
+
+  if (id == 0) {
+    // Obtain the column name, data type and data rank in child[0]
+    column_name_id_ = child_[id]->column_name_id_map();
+    for (auto item : new_row) {
+      data_type_.push_back(item->type());
+      data_rank_.push_back(item->Rank());
+    }
+  } else {
+    // Compare the column name, data type and data rank with these in child[0]
+    if (child_[id]->column_name_id_map() != column_name_id_) {
+      RETURN_STATUS_UNEXPECTED("The column name or column order is not the same with previous dataset.");
+    }
+    int32_t index = 0;
+    for (auto item : new_row) {
+      if ((item->type() != data_type_[index]) || item->Rank() != data_rank_[index++]) {
+        RETURN_STATUS_UNEXPECTED("The data type or data rank is not the same with previous dataset.");
+      }
+    }
+  }
+  return Status::OK();
+}
+
+Status ConcatOp::PrepareNodePostAction() {
+  RETURN_IF_NOT_OK(PipelineOp::PrepareNodePostAction());
+  tree_->AddToRepeatStack(shared_from_this());
+  return Status::OK();
+}
+}  // namespace dataset
+}  // namespace mindspore

mindspore/ccsrc/dataset/engine/datasetops/concat_op.h

@@ -0,0 +1,95 @@
+/**
+ * Copyright 2020 Huawei Technologies Co., Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef DATASET_ENGINE_DATASETOPS_CONCAT_OP_H_
+#define DATASET_ENGINE_DATASETOPS_CONCAT_OP_H_
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <vector>
+#include "dataset/engine/datasetops/pipeline_op.h"
+
+namespace mindspore {
+namespace dataset {
+class ConcatOp : public PipelineOp {
+ public:
+  // The nested builder class inside of the ConcatOp is used to help manage all of the arguments
+  // for constructing it.  This Concat op is very simple though, so this builder is really just
+  // provided for a consistent look and feel for creators of Dataset operators overall.
+  class Builder {
+   public:
+    // Builder constructor. Creates the builder object.
+    // @note No default args
+    // @return This is a constructor.
+    Builder();
+
+    // Default destructor
+    ~Builder() = default;
+
+    // The builder "build" method creates the final object.
+    // @return shared_ptr to the new StorageOp object
+    Status Build(std::shared_ptr<ConcatOp> *);
+
+   private:
+    int32_t builder_op_connector_size_;
+  };
+
+  // Constructor of the ConcatOp.
+  // @note The builder class should be used to call it
+  // @param op_connector_size - connector size
+  explicit ConcatOp(int32_t op_connector_size);
+
+  // Destructor
+  ~ConcatOp() = default;
+
+  // A print method typically used for debugging
+  // @param out - The output stream to write output to
+  // @param show_all - A bool to control if you want to show all info or just a summary
+  void Print(std::ostream &out, bool show_all) const override;
+
+  // << Stream output operator overload
+  // @notes This allows you to write the debug print info using stream operators
+  // @param out - reference to the output stream being overloaded
+  // @param ro - reference to the ConcatOp to display
+  // @return - the output stream must be returned
+  friend std::ostream &operator<<(std::ostream &out, const ConcatOp &ro) {
+    ro.Print(out, false);
+    return out;
+  }
+
+  // All dataset ops operate by launching a thread (see ExecutionTree). This class functor will
+  // provide the master loop that drives the logic for performing the work
+  // @return Status - The error code return
+  Status operator()() override;
+
+  // During tree prepare phase, operators may have specific post-operations to perform depending on
+  // their role.
+  // @notes Derived versions of this function should always call it's superclass version first
+  // before providing their own implementations.
+  Status PrepareNodePostAction() override;
+
+ private:
+  Status Verify(int32_t id, const std::unique_ptr<DataBuffer> &buf);
+
+  int32_t children_num_;                                     // The num of child of parent node.
+  std::unordered_map<std::string, int32_t> column_name_id_;  // Mapping between col index and col name
+  std::vector<DataType> data_type_;
+  std::vector<dsize_t> data_rank_;
+};
+}  // namespace dataset
+}  // namespace mindspore
+
+#endif  // DATASET_ENGINE_DATASETOPS_CONCAT_OP_H_

mindspore/dataset/engine/datasets.py

@@ -44,7 +44,7 @@ from .validators import check, check_batch, check_shuffle, check_map, check_filt
     check_rename, \
     check_take, check_project, check_imagefolderdatasetv2, check_mnist_cifar_dataset, check_manifestdataset, \
     check_tfrecorddataset, check_vocdataset, check_celebadataset, check_minddataset, check_generatordataset, \
-    check_sync_wait, check_zip_dataset, check_add_column, check_textfiledataset
+    check_sync_wait, check_zip_dataset, check_add_column, check_textfiledataset, check_concat
 from ..core.datatypes import mstype_to_detype, mstypelist_to_detypelist
 
 try:
@@ -147,6 +147,9 @@ class Dataset:
         self._repeat_count = None
         self._sync = False
 
+    def __add__(self, datasets):
+        return self.concat(datasets)
+
     def get_args(self):
         """
         Returns attributes (member variables) related to the current class.
@@ -560,6 +563,37 @@ class Dataset:
             raise TypeError("The zip function %s type error!" % (datasets))
         return ZipDataset(datasets)
 
+    @check_concat
+    def concat(self, datasets):
+        """
+        Concat the datasets in the input list of datasets, supported using "+" to reload concat operation.
+
+        Note:
+        The column name，column data type and rank of column data should be the same in input datasets.
+
+        Args:
+            datasets (list or class Dataset): A list of datasets or a single class Dataset
+                to be concated together with this dataset.
+
+        Returns:
+            ConcatDataset, dataset concated.
+
+        Examples:
+            >>> import mindspore.dataset as ds
+            >>> # ds1 and ds2 are instances of Dataset object
+            >>> # creates a dataset by concating ds1 and ds2 with "+" operation
+            >>> data1 = ds1 + ds2
+            >>> # creates a dataset by concating ds1 and ds2 with concat operation
+            >>> data1 = ds1.concat(ds2)
+        """
+        if isinstance(datasets, Dataset):
+            datasets = [self] + [datasets]
+        elif isinstance(datasets, list):
+            datasets = [self] + datasets
+        else:
+            raise TypeError("The concat_dataset function %s type error!" % (datasets))
+        return ConcatDataset(datasets)
+
     @check_rename
     def rename(self, input_columns, output_columns):
         """
@@ -1658,6 +1692,39 @@ class ZipDataset(DatasetOp):
         return args
 
 
+class ConcatDataset(DatasetOp):
+    """
+    The result of applying concat dataset operator to the input Dataset.
+
+    Args:
+        datasets (list): A list of datasets to be concated together.
+
+    Raises:
+        TypeError: If dataset is not an instance of Dataset.
+    """
+
+    def __init__(self, datasets):
+        super().__init__()
+        for dataset in datasets:
+            if not isinstance(dataset, Dataset):
+                raise TypeError("The parameter %s of concat has type error!" % (dataset))
+        self.datasets = datasets
+        for data in datasets:
+            self.input.append(data)
+            data.output.append(self)
+
+    def get_dataset_size(self):
+        """
+        Get the number of batches in an epoch.
+
+        Return:
+            Number, number of batches.
+        """
+        children_sizes = [c.get_dataset_size() for c in self.input]
+        dataset_size = np.sum(children_sizes)
+        return dataset_size
+
+
 class RenameDataset(DatasetOp):
     """
     The result of applying Rename operator to the input Dataset.

mindspore/dataset/engine/iterators.py

@@ -156,6 +156,8 @@ class Iterator:
             op_type = OpName.BARRIER
         elif isinstance(dataset, de.ZipDataset):
             op_type = OpName.ZIP
+        elif isinstance(dataset, de.ConcatDataset):
+            op_type = OpName.CONCAT
         elif isinstance(dataset, de.MapDataset):
             op_type = OpName.MAP
         elif isinstance(dataset, de.FilterDataset):

mindspore/dataset/engine/serializer_deserializer.py

@@ -335,6 +335,10 @@ def create_node(node):
         # Create ZipDataset instance, giving dummy input dataset that will be overrided in the caller.
         pyobj = de.ZipDataset((de.Dataset(), de.Dataset()))
 
+    elif dataset_op == 'ConcatDataset':
+        # Create ConcatDataset instance, giving dummy input dataset that will be overrided in the caller.
+        pyobj = de.ConcatDataset((de.Dataset(), de.Dataset()))
+
     elif dataset_op == 'RenameDataset':
         pyobj = de.Dataset().rename(node['input_columns'], node['output_columns'])
 

mindspore/dataset/engine/validators.py

@@ -902,6 +902,26 @@ def check_zip_dataset(method):
     return new_method
 
 
+def check_concat(method):
+    """check the input arguments of concat_dataset method in `Dataset`."""
+
+    @wraps(method)
+    def new_method(*args, **kwargs):
+        param_dict = make_param_dict(method, args, kwargs)
+
+        # check datasets; required argument
+        ds = param_dict.get("datasets")
+        if ds is None:
+            raise ValueError("datasets is not provided.")
+
+        if not isinstance(ds, (list, datasets.Dataset)):
+            raise ValueError("datasets is not list or of type Dataset.")
+
+        return method(*args, **kwargs)
+
+    return new_method
+
+
 def check_rename(method):
     """check the input arguments of rename."""
 

tests/ut/cpp/dataset/CMakeLists.txt

@@ -66,6 +66,7 @@ SET(DE_UT_SRCS
     take_op_test.cc
     text_file_op_test.cc
     filter_op_test.cc
+    concat_op_test.cc
     )
 
 add_executable(de_ut_tests ${DE_UT_SRCS})

tests/ut/cpp/dataset/concat_op_test.cc

@@ -0,0 +1,125 @@
+/**
+ * Copyright 2020 Huawei Technologies Co., Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <iostream>
+#include <memory>
+#include <vector>
+
+#include "common/common.h"
+#include "common/utils.h"
+#include "dataset/core/client.h"
+#include "gtest/gtest.h"
+#include "utils/log_adapter.h"
+
+namespace common = mindspore::common;
+
+using namespace mindspore::dataset;
+using mindspore::MsLogLevel::INFO;
+using mindspore::ExceptionType::NoExceptionType;
+using mindspore::LogStream;
+
+class MindDataTestConcatOp : public UT::DatasetOpTesting {};
+
+
+TEST_F(MindDataTestConcatOp, TestConcatProject) {
+/* Tree:
+ *
+ *            OpId(2) ConcatOp
+ *            /               \
+ *     OpId(0) TFReaderOp    OpId(1) TFReaderOp
+ *
+ * Start with an empty execution tree
+*/
+  MS_LOG(INFO) << "UT test TestConcatProject.";
+  auto my_tree = std::make_shared<ExecutionTree>();
+
+  std::string dataset_path;
+  dataset_path = datasets_root_path_ + "/testTFTestAllTypes/test.data";
+
+  // TFReaderOp1
+  std::shared_ptr<TFReaderOp> my_tfreader_op1;
+  TFReaderOp::Builder builder1;
+  builder1.SetDatasetFilesList({dataset_path})
+    .SetRowsPerBuffer(16)
+    .SetWorkerConnectorSize(16)
+    .SetNumWorkers(16);
+  std::unique_ptr<DataSchema> schema1 = std::make_unique<DataSchema>();
+  schema1->LoadSchemaFile(datasets_root_path_ + "/testTFTestAllTypes/datasetSchema.json", {});
+  builder1.SetDataSchema(std::move(schema1));
+  Status rc = builder1.Build(&my_tfreader_op1);
+  ASSERT_TRUE(rc.IsOk());
+  rc = my_tree->AssociateNode(my_tfreader_op1);
+  ASSERT_TRUE(rc.IsOk());
+
+  // TFReaderOp2
+  std::shared_ptr<TFReaderOp> my_tfreader_op2;
+  TFReaderOp::Builder builder2;
+  builder2.SetDatasetFilesList({dataset_path})
+    .SetRowsPerBuffer(16)
+    .SetWorkerConnectorSize(16)
+    .SetNumWorkers(16);
+  std::unique_ptr<DataSchema> schema2 = std::make_unique<DataSchema>();
+  schema2->LoadSchemaFile(datasets_root_path_ + "/testTFTestAllTypes/datasetSchema.json", {});
+  builder2.SetDataSchema(std::move(schema2));
+  rc = builder2.Build(&my_tfreader_op2);
+  ASSERT_TRUE(rc.IsOk());
+  rc = my_tree->AssociateNode(my_tfreader_op2);
+  ASSERT_TRUE(rc.IsOk());
+
+  // Creating ConcatOp
+  std::shared_ptr<ConcatOp> concat_op;
+  rc = ConcatOp::Builder().Build(&concat_op);
+  EXPECT_TRUE(rc.IsOk());
+
+  rc = my_tree->AssociateNode(concat_op);
+  EXPECT_TRUE(rc.IsOk());
+  rc = concat_op->AddChild(std::move(my_tfreader_op1));
+  EXPECT_TRUE(rc.IsOk());
+  rc = concat_op->AddChild(std::move(my_tfreader_op2));
+  EXPECT_TRUE(rc.IsOk());
+  rc = my_tree->AssignRoot(concat_op);
+  EXPECT_TRUE(rc.IsOk());
+  rc = my_tree->Prepare();
+  EXPECT_TRUE(rc.IsOk());
+
+  // Launch the tree execution to kick off threads and start running the pipeline
+  MS_LOG(INFO) << "Launching my tree.";
+  rc = my_tree->Launch();
+  EXPECT_TRUE(rc.IsOk());
+
+  // Simulate a parse of data from our pipeline.
+  std::shared_ptr<DatasetOp> rootNode = my_tree->root();
+
+  DatasetIterator di(my_tree);
+  TensorRow tensor_list;
+  rc = di.FetchNextTensorRow(&tensor_list);
+  EXPECT_TRUE(rc.IsOk());
+
+  int row_count = 0;
+  while (!tensor_list.empty()) {
+    MS_LOG(INFO) << "Row display for row #: " << row_count << ".";
+
+    // Display the tensor by calling the printer on it
+    for (int i = 0; i < tensor_list.size(); i++) {
+      std::ostringstream ss;
+      ss << "(" << tensor_list[i] << "): " << *tensor_list[i] << std::endl;
+      MS_LOG(INFO) << "Tensor print: " << common::SafeCStr(ss.str()) << ".";
+    }
+    rc = di.FetchNextTensorRow(&tensor_list);
+    EXPECT_TRUE(rc.IsOk());
+    row_count++;
+  }
+  ASSERT_EQ(row_count, 24); // Should be 24 rows fetched
+}

tests/ut/python/dataset/test_concat.py

@@ -0,0 +1,377 @@
+# Copyright 2020 Huawei Technologies Co., Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+import mindspore.dataset as ds
+import mindspore.dataset.transforms.vision.py_transforms as F
+import mindspore.dataset.transforms.c_transforms as C
+import mindspore.common.dtype as mstype
+from mindspore import log as logger
+import numpy as np
+
+
+# In generator dataset: Number of rows is 3, its value is 0, 1, 2
+def generator():
+    for i in range(3):
+        yield np.array([i]),
+
+
+# In generator_10 dataset: Number of rows is 7, its value is 3, 4, 5 ... 10
+def generator_10():
+    for i in range(3, 10):
+        yield np.array([i]),
+
+# In generator_20 dataset: Number of rows is 10, its value is 10, 11, 12 ... 20
+def generator_20():
+    for i in range(10, 20):
+        yield np.array([i]),
+
+
+def test_concat_01():
+    """
+    Test concat: test concat 2 datasets that have the same column name and data type
+    """
+    logger.info("test_concat_01")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col1"])
+
+    data3 = data1 + data2
+
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(data3):
+        logger.info("data: %i", d[0][0])
+        assert i == d[0][0]
+
+    assert sum([1 for _ in data3]) == 10
+
+
+def test_concat_02():
+    """
+    Test concat: test concat 2 datasets using concat operation not "+" operation
+    """
+    logger.info("test_concat_02")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col1"])
+
+    data3 = data1.concat(data2)
+
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(data3):
+        logger.info("data: %i", d[0][0])
+        assert i == d[0][0]
+
+    assert sum([1 for _ in data3]) == 10
+
+
+def test_concat_03():
+    """
+    Test concat: test concat dataset that has different column
+    """
+    logger.info("test_concat_03")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col2"])
+
+    data3 = data1 + data2
+
+    try:
+        for i, d in enumerate(data3):
+            pass
+        assert False
+    except RuntimeError:
+        pass
+
+
+def test_concat_04():
+    """
+    Test concat: test concat dataset that has different rank
+    """
+    logger.info("test_concat_04")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col2"])
+    data2 = data2.batch(3)
+
+    data3 = data1 + data2
+
+    try:
+        for i, d in enumerate(data3):
+            pass
+        assert False
+    except RuntimeError:
+        pass
+
+
+def test_concat_05():
+    """
+    Test concat: test concat dataset that has different data type
+    """
+    logger.info("test_concat_05")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col1"])
+
+    type_cast_op = C.TypeCast(mstype.float32)
+    data1 = data1.map(input_columns=["col1"], operations=type_cast_op)
+
+    data3 = data1 + data2
+
+    try:
+        for i, d in enumerate(data3):
+            pass
+        assert False
+    except RuntimeError:
+        pass
+
+
+def test_concat_06():
+    """
+    Test concat: test concat muti datasets in one time
+    """
+    logger.info("test_concat_06")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col1"])
+    data3 = ds.GeneratorDataset(generator_20, ["col1"])
+
+    dataset = data1 + data2 + data3
+
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(dataset):
+        logger.info("data: %i", d[0][0])
+        assert i == d[0][0]
+
+    assert sum([1 for _ in dataset]) == 20
+
+
+def test_concat_07():
+    """
+    Test concat: test concat one dataset with multi datasets (datasets list)
+    """
+    logger.info("test_concat_07")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col1"])
+    data3 = ds.GeneratorDataset(generator_20, ["col1"])
+
+    dataset = [data2] + [data3]
+    data4 = data1 + dataset
+
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(data4):
+        logger.info("data: %i", d[0][0])
+        assert i == d[0][0]
+
+    assert sum([1 for _ in data4]) == 20
+
+
+def test_concat_08():
+    """
+    Test concat: test concat 2 datasets, and then repeat
+    """
+    logger.info("test_concat_08")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col1"])
+
+    data3 = data1 + data2
+    data3 = data3.repeat(2)
+
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(data3):
+        logger.info("data: %i", d[0][0])
+        assert i % 10 == d[0][0]
+
+    assert sum([1 for _ in data3]) == 20
+
+
+def test_concat_09():
+    """
+    Test concat: test concat 2 datasets, both of them have been repeat before
+    """
+    logger.info("test_concat_09")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col1"])
+
+    data1 = data1.repeat(2)
+    data2 = data2.repeat(2)
+    data3 = data1 + data2
+
+    res = [0, 1, 2, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 3, 4, 5, 6, 7, 8, 9]
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(data3):
+        logger.info("data: %i", d[0][0])
+        assert res[i] == d[0][0]
+
+    assert sum([1 for _ in data3]) == 20
+
+
+def test_concat_10():
+    """
+    Test concat: test concat 2 datasets, one of them have repeat before
+    """
+    logger.info("test_concat_10")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col1"])
+
+    data1 = data1.repeat(2)
+    data3 = data1 + data2
+
+    res = [0, 1, 2, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(data3):
+        logger.info("data: %i", d[0][0])
+        assert res[i] == d[0][0]
+
+    assert sum([1 for _ in data3]) == 13
+
+
+def test_concat_11():
+    """
+    Test concat: test dataset batch then concat
+    """
+    logger.info("test_concat_11")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_20, ["col1"])
+
+    data1 = data1.batch(3)
+    data2 = data2.batch(5)
+
+    data3 = data1 + data2
+    res = [0, 10, 15, 20]
+
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(data3):
+        logger.info("data: %i", d[0][0])
+        assert res[i] == d[0][0]
+
+    assert sum([1 for _ in data3]) == 3
+
+
+def test_concat_12():
+    """
+    Test concat: test dataset concat then shuffle
+    """
+    logger.info("test_concat_12")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_10, ["col1"])
+
+    data1.set_dataset_size(3)
+    data2.set_dataset_size(7)
+
+    data3 = data1 + data2
+    res = [8, 6, 2, 5, 0, 4, 9, 3, 7, 1]
+
+    ds.config.set_seed(1)
+    assert data3.get_dataset_size() == 10
+    data3 = data3.shuffle(buffer_size=10)
+
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(data3):
+        logger.info("data: %i", d[0][0])
+        assert res[i] == d[0][0]
+
+    assert sum([1 for _ in data3]) == 10
+
+
+def test_concat_13():
+    """
+    Test concat: test dataset batch then shuffle and concat
+    """
+    logger.info("test_concat_13")
+    data1 = ds.GeneratorDataset(generator, ["col1"])
+    data2 = ds.GeneratorDataset(generator_20, ["col1"])
+
+    data1.set_dataset_size(3)
+    data2.set_dataset_size(10)
+
+    data1 = data1.batch(3)
+    data2 = data2.batch(5)
+
+    data3 = data1 + data2
+    res = [15, 0, 10]
+
+    ds.config.set_seed(1)
+    assert data3.get_dataset_size() == 3
+
+    data3 = data3.shuffle(buffer_size=int(data3.get_dataset_size()))
+
+    # Here i refers to index, d refers to data element
+    for i, d in enumerate(data3):
+        logger.info("data: %i", d[0][0])
+        assert res[i] == d[0][0]
+
+    assert sum([1 for _ in data3]) == 3
+
+
+def test_concat_14():
+    """
+    Test concat: create dataset with different dataset folder, and do diffrent operation then concat
+    """
+    logger.info("test_concat_14")
+    DATA_DIR = "../data/dataset/testPK/data"
+    DATA_DIR2 = "../data/dataset/testImageNetData/train/"
+
+    data1 = ds.ImageFolderDatasetV2(DATA_DIR, num_samples=3)
+    data2 = ds.ImageFolderDatasetV2(DATA_DIR2, num_samples=2)
+
+    transforms1 = F.ComposeOp([F.Decode(),
+                               F.Resize((224,224)),
+                               F.ToTensor()])
+
+    data1 = data1.map(input_columns=["image"], operations=transforms1())
+    data2 = data2.map(input_columns=["image"], operations=transforms1())
+    data3 = data1 + data2
+
+    expected, output = [], []
+    for d in data1:
+        expected.append(d[0])
+    for d in data2:
+        expected.append(d[0])
+    for d in data3:
+        output.append(d[0])
+
+    assert len(expected) == len(output)
+    np.array_equal(np.array(output), np.array(expected))
+
+    assert sum([1 for _ in data3]) == 5
+    assert data3.get_dataset_size() == 5
+
+
+def test_concat_15():
+    """
+    Test concat: create dataset with different format of dataset file, and then concat
+    """
+    logger.info("test_concat_15")
+    DATA_DIR = "../data/dataset/testPK/data"
+    DATA_DIR2 = ["../data/dataset/test_tf_file_3_images/train-0000-of-0001.data"]
+
+    data1 = ds.ImageFolderDatasetV2(DATA_DIR)
+    data2 = ds.TFRecordDataset(DATA_DIR2, columns_list=["image"])
+
+    data1 = data1.project(["image"])
+    data3 = data1 + data2
+
+    assert sum([1 for _ in data3]) == 47
+
+
+if __name__ == "__main__":
+    test_concat_01()
+    test_concat_02()
+    test_concat_03()
+    test_concat_04()
+    test_concat_05()
+    test_concat_06()
+    test_concat_07()
+    test_concat_08()
+    test_concat_09()
+    test_concat_10()
+    test_concat_11()
+    test_concat_12()
+    test_concat_13()
+    test_concat_14()
+    test_concat_15()