expose OutputFormatEnum instead of ResultFormat to user (#484)

expose OutputFormatEnum instead of ResultFormat to user; mention in the documentation

Author: ponyisi

docs/transform_request.rst

@@ -32,7 +32,7 @@ The General Section
 ^^^^^^^^^^^^^^^^^^^
 The General section of the request includes the following fields:
 
-* (Optional) ``OutputFormat``: Can be ``root-ttree`` (default) or ``parquet``
+* (Optional) ``OutputFormat``: Can be ``root-ttree`` (default) or ``parquet`` (you can also use the enums ``servicex.OutputFormat.root_ttree`` and ``servicex.OutputFormat.parquet``)
 * (Optional) ``Delivery``: Can be ``URLs`` or ``LocalCache`` (default)
 
 In general, if you are running on your laptop away from the ServiceX site and are working with a small amount of

servicex/__init__.py

@@ -27,12 +27,14 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 from servicex.databinder_models import Sample, General, ServiceXSpec
 from servicex.servicex_client import deliver
-from .models import ResultFormat, ResultDestination
+from .models import ResultDestination
 import servicex.dataset as dataset
 import servicex.query as query
 
+OutputFormat = General.OutputFormatEnum
+
 __all__ = [
-    "ResultFormat",
+    "OutputFormat",
     "ResultDestination",
     "Sample",
     "General",

tests/test_databinder.py

@@ -2,7 +2,7 @@
 from unittest.mock import patch
 from pydantic import ValidationError
 
-from servicex import ServiceXSpec, dataset
+from servicex import ServiceXSpec, dataset, OutputFormat
 from servicex.query_core import ServiceXException
 from servicex.servicex_client import ReturnValueException
 from servicex.dataset import FileList, Rucio
@@ -93,6 +93,21 @@ def test_list_of_root_files():
     ]
 
 
+def test_output_format():
+    spec = basic_spec()
+    spec['General'] = {'OutputFormat': 'root-ttree'}
+    ServiceXSpec.model_validate(spec)
+    spec['General'] = {'OutputFormat': 'parquet'}
+    ServiceXSpec.model_validate(spec)
+    spec['General'] = {'OutputFormat': OutputFormat.root_ttree}
+    ServiceXSpec.model_validate(spec)
+    spec['General'] = {'OutputFormat': OutputFormat.parquet}
+    ServiceXSpec.model_validate(spec)
+    with pytest.raises(ValidationError):
+        spec['General'] = {'OutputFormat': 'root-tree'}
+        ServiceXSpec.model_validate(spec)
+
+
 def test_rucio_did():
     spec = ServiceXSpec.model_validate(
         basic_spec(

tests/test_dataset_group.py

@@ -29,7 +29,7 @@
 
 import pytest
 
-from servicex import ResultFormat
+from servicex.models import ResultFormat
 from servicex.dataset_group import DatasetGroup
 from servicex.query_core import ServiceXException