Add code for creating a dataset using path on datastore (#73)

* Add code for creating a dataset using path on datastore

* OutputFileDatasetConfig example

* Example for registering from local

* update warning

* address comments

* Fix import

website/docs/cheatsheets/python/v1/data.md

@@ -251,6 +251,46 @@ config.run_config.data_references[data_ref.data_reference_name] = data_ref.to_co
 ## Create Dataset
 
 ### From local data
+You could create and register a dataset directly from a folder on your local machine. Note that `src_dir` must point to a **folder**, not file.
+
+:warning: Method `upload_directory`: This is an experimental method, and may change at any time. Please see https://aka.ms/azuremlexperimental for more information.
+```python
+from azureml.core import Dataset
+
+# upload the data to datastore and create a FileDataset from it 
+folder_data = Dataset.File.upload_directory(src_dir="path/to/folder", target=(datastore, "self-defined/path/on/datastore"))
+dataset = folder_data.register(workspace=ws, name="<dataset_name>")
+```
+
+### From a datastore
+The code snippet below shows how to create a `Dataset` given a relative path on `datastore`. Note that the path could either point to a folder (e.g. `local/test/`) or a single file (e.g. `local/test/data.tsv`).
+```python
+from azureml.core import Dataset
+
+# create input dataset
+data = Dataset.File.from_files(path=(datastore, "path/on/datastore"))
+dataset = data.register(workspace=ws, name="<dataset_name>")
+```
+
+### From outputs using `OutputFileDatasetConfig`
+```python
+from azureml.core import ScriptRunConfig
+from azureml.data import OutputFileDatasetConfig
+
+output_data = OutputFileDatasetConfig(
+    destination=(datastore, "path/on/datastore"),
+    name="<output_name>",
+)
+
+config = ScriptRunConfig(
+        source_directory=".",
+        script="run.py",
+        arguments=["--output_dir", output_data.as_mount()],
+)
+
+# register your OutputFileDatasetConfig as a dataset
+output_data_dataset = output_data.register_on_complete(name="<dataset_name>", description = "<dataset_description>")
+```
 
 #### Upload to datastore