Append table_create with if_not_exists param

rethinkengine/document.py

@@ -114,9 +114,17 @@ def items(self):
         return [(k, self._get_value(k)) for k in self._fields]
 
     @classmethod
-    def table_create(cls):
-        return r.table_create(cls.Meta.table_name,
-            primary_key=cls.Meta.primary_key_field).run(get_conn())
+    def table_create(cls, if_not_exists=True):
+        if (
+            if_not_exists and
+            (cls.Meta.table_name in r.table_list().run(get_conn()))
+        ):
+            return
+
+        return r.table_create(
+            cls.Meta.table_name,
+            primary_key=cls.Meta.primary_key_field
+        ).run(get_conn())
 
     @classmethod
     def table_drop(cls):

tests/document/test_create_table.py

@@ -0,0 +1,17 @@
+from .. import Foo
+
+import rethinkdb as r
+import unittest2 as unittest
+
+
+class CreateTableTestCase(unittest.TestCase):
+    def tearDown(self):
+        # recreate Foo table
+        Foo.table_create()
+
+    def test_create(self):
+        Foo.table_drop()
+        Foo.table_create()
+        Foo.table_create()
+        with self.assertRaises(r.RqlRuntimeError):
+            Foo.table_create(if_not_exists=False)