From 70621da09e9cdddeb2c05645a1f378bdd56c6e5a Mon Sep 17 00:00:00 2001
From: Son CHU <sonlac@users.noreply.github.com>
Date: Tue, 18 Jul 2017 23:16:30 +0200
Subject: [PATCH] Add `is_nullable` method to check for `NULLABLE` mode (#3620)

Resolves: #3548
---
 bigquery/google/cloud/bigquery/dbapi/cursor.py |  2 +-
 bigquery/google/cloud/bigquery/schema.py       |  5 +++++
 bigquery/tests/unit/test_schema.py             | 10 ++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/bigquery/google/cloud/bigquery/dbapi/cursor.py b/bigquery/google/cloud/bigquery/dbapi/cursor.py
index 4398eec20b88..bcbb19cfd066 100644
--- a/bigquery/google/cloud/bigquery/dbapi/cursor.py
+++ b/bigquery/google/cloud/bigquery/dbapi/cursor.py
@@ -76,7 +76,7 @@ def _set_description(self, schema):
                 internal_size=None,
                 precision=None,
                 scale=None,
-                null_ok=field.mode == 'NULLABLE')
+                null_ok=field.is_nullable)
             for field in schema])
 
     def _set_rowcount(self, query_results):
diff --git a/bigquery/google/cloud/bigquery/schema.py b/bigquery/google/cloud/bigquery/schema.py
index faec69f616da..edd8dd68f3bd 100644
--- a/bigquery/google/cloud/bigquery/schema.py
+++ b/bigquery/google/cloud/bigquery/schema.py
@@ -65,6 +65,11 @@ def mode(self):
         """
         return self._mode
 
+    @property
+    def is_nullable(self):
+        """Check whether 'mode' is 'nullable'."""
+        return self._mode == 'NULLABLE'
+
     @property
     def description(self):
         """Optional[str]: Description for the field."""
diff --git a/bigquery/tests/unit/test_schema.py b/bigquery/tests/unit/test_schema.py
index 018736d31bc1..bf3cf2e025d1 100644
--- a/bigquery/tests/unit/test_schema.py
+++ b/bigquery/tests/unit/test_schema.py
@@ -74,6 +74,16 @@ def test_mode_property(self):
         schema_field = self._make_one('again', 'FLOAT', mode=mode)
         self.assertIs(schema_field.mode, mode)
 
+    def test_is_nullable(self):
+        mode = 'NULLABLE'
+        schema_field = self._make_one('test', 'FLOAT', mode=mode)
+        self.assertTrue(schema_field.is_nullable)
+
+    def test_is_not_nullable(self):
+        mode = 'REPEATED'
+        schema_field = self._make_one('test', 'FLOAT', mode=mode)
+        self.assertFalse(schema_field.is_nullable)
+
     def test_description_property(self):
         description = 'It holds some data.'
         schema_field = self._make_one(