MAINT: Consolidate coercion to sqlite conn/eng

zipline/utils/sqlite_utils.py

@@ -12,9 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import sqlite3
 
+import sqlalchemy as sa
 from six.moves import range
 
+from .input_validation import coerce_string
+
 SQLITE_MAX_VARIABLE_NUMBER = 998
 
 
@@ -22,3 +26,9 @@ def group_into_chunks(items, chunk_size=SQLITE_MAX_VARIABLE_NUMBER):
     items = list(items)
     return [items[x:x+chunk_size]
             for x in range(0, len(items), chunk_size)]
+
+
+coerce_string_to_conn = coerce_string(sqlite3.connect)
+coerce_string_to_eng = coerce_string(
+    lambda s: sa.create_engine('sqlite:///' + s)
+)