!872 [Dataset] Add schema support for GeneratorDataset

Merge pull request !872 from JunhanHu/generator_schema

mindspore/dataset/engine/datasets.py

@@ -2504,11 +2504,12 @@ class GeneratorDataset(SourceDataset):
             Iterable source is required to return a tuple of numpy array as a row of the dataset on iter(source).next().
             Random accessible source is required to return a tuple of numpy array as a row of the dataset on
             source[idx].
-        column_names (list[str]): List of column names of the dataset.
+        column_names (list[str], optional): List of column names of the dataset (default=None). Users are required to
+            provide either column_names or schema.
         column_types (list[mindspore.dtype], optional): List of column data types of the dataset (default=None).
             If provided, sanity check will be performed on generator output.
-        schema (Schema/String, optional): Path to the json schema file or schema object (default=None).
-            If the schema is not provided, the meta data from column_names and column_types is considered the schema.
+        schema (Schema/String, optional): Path to the json schema file or schema object (default=None). Users are
+            required to provide either column_names or schema. If both are provided, schema will be used.
         num_samples (int, optional): The number of samples to be included in the dataset
             (default=None, all images).
         num_parallel_workers (int, optional): Number of subprocesses used to fetch the dataset in parallel (default=1).
@@ -2555,8 +2556,8 @@ class GeneratorDataset(SourceDataset):
     """
 
     @check_generatordataset
-    def __init__(self, source, column_names, column_types=None, schema=None, num_samples=None, num_parallel_workers=1,
-                 shuffle=None, sampler=None, num_shards=None, shard_id=None):
+    def __init__(self, source, column_names=None, column_types=None, schema=None, num_samples=None,
+                 num_parallel_workers=1, shuffle=None, sampler=None, num_shards=None, shard_id=None):
         super().__init__(num_parallel_workers)
         self.sampler = _select_sampler(num_samples, sampler, shuffle, num_shards, shard_id)
         if self.sampler is not None and hasattr(source, "__getitem__"):
@@ -2598,6 +2599,16 @@ class GeneratorDataset(SourceDataset):
         else:
             self.column_types = column_types
 
+        if schema is not None:
+            self.schema = schema
+            if not isinstance(schema, Schema):
+                self.schema = Schema(schema)
+            self.column_names = []
+            self.column_types = []
+            for col in self.schema.columns:
+                self.column_names.append(col["name"])
+                self.column_types.append(DataType(col["type"]))
+
     def get_args(self):
         args = super().get_args()
         args["source"] = self.source

mindspore/dataset/engine/validators.py

@@ -555,10 +555,15 @@ def check_generatordataset(method):
             except TypeError:
                 raise TypeError("source should be callable, iterable or random accessible")
 
-        # check column_names; required argument
+        # check column_names or schema; required argument
         column_names = param_dict.get('column_names')
-        if column_names is None:
-            raise ValueError("column_names is not provided.")
+        schema = param_dict.get('schema')
+        if column_names is None and schema is None:
+            raise ValueError("Neither columns_names not schema are provided.")
+
+        if schema is not None:
+            if not isinstance(schema, datasets.Schema) and not isinstance(schema, str):
+                raise ValueError("schema should be a path to schema file or a schema object.")
 
         # check optional argument
         nreq_param_int = ["num_samples", "num_parallel_workers", "num_shards", "shard_id"]

tests/ut/python/dataset/test_generator.py

@@ -580,6 +580,41 @@ def test_num_samples_underflow():
         count = count + 1
     assert count == 64
 
+
+def type_tester_with_type_check_2c_schema(t, c):
+    logger.info("Test with Type {}".format(t.__name__))
+
+    schema = ds.Schema()
+    schema.add_column("data0", c[0])
+    schema.add_column("data1", c[1])
+
+    # apply dataset operations
+    data1 = ds.GeneratorDataset((lambda: generator_with_type_2c(t)), schema=schema)
+
+    data1 = data1.batch(4)
+
+    i = 0
+    for item in data1.create_dict_iterator():  # each data is a dictionary
+        golden = np.array([[i], [i + 1], [i + 2], [i + 3]], dtype=t)
+        assert np.array_equal(item["data0"], golden)
+        i = i + 4
+
+
+def test_schema():
+    """
+    Test 2 column Generator on different data type with type check with schema input
+    """
+    logger.info("Test 2 column Generator on all data types with type check")
+
+    np_types = [np.int8, np.int16, np.int32, np.int64, np.uint8, np.uint16, np.uint32, np.uint64, np.float32,
+                np.float64]
+    de_types = [mstype.int8, mstype.int16, mstype.int32, mstype.int64, mstype.uint8, mstype.uint16, mstype.uint32,
+                mstype.uint64, mstype.float32, mstype.float64]
+
+    for i in range(len(np_types)):
+        type_tester_with_type_check_2c_schema(np_types[i], [de_types[i], de_types[i]])
+
+
 def manual_test_keyborad_interrupt():
     """
     Test keyborad_interrupt
@@ -626,5 +661,6 @@ if __name__ == "__main__":
     test_sequential_sampler()
     test_distributed_sampler()
     test_random_sampler()
+    test_schema()