Update readme

mxmzdlv · mxmzdlv · commit f33f7a1945d8 · 2018-04-28T00:23:31.000+12:00
diff --git a/README.rst b/README.rst
@@ -16,10 +16,21 @@ Usage
 
 Project
 _______
+
 ``project`` in ``bigquery://project`` is used to instantiate BigQuery client with the specific project ID. To infer project from the environment, use ``bigquery://`` – without ``project``
 
+Authentication
+_______
+
+Follow the `Google Cloud library guide <https://google-cloud-python.readthedocs.io/en/latest/core/auth.html#overview>`_ for authentication. Alternatively, you can provide the path to a service account JSON file in ``create_engine()``:
+
+.. code-block:: python
+
+    engine = create_engine('bigquery://project', credentials_path='/path/to/keyfile.json')
+
 Table names
 ___________
+
 To query tables from non-default projects, use the following format for the table name: ``project.dataset.table``, e.g.:
 
 .. code-block:: python
