Transform dates from crate to python datetime

In execute(), transform the columns with type timestamp and timestamp without time zone to python datetime, this will correctly display dates in apache superset

src/crate/client/cursor.py

@@ -22,6 +22,7 @@
 from .exceptions import ProgrammingError
 from distutils.version import StrictVersion
 import warnings
+from datetime import datetime
 
 BULK_INSERT_MIN_VERSION = StrictVersion("0.42.0")
 
@@ -53,8 +54,35 @@ def execute(self, sql, parameters=None, bulk_parameters=None):
         self._result = self.connection.client.sql(sql, parameters,
                                                   bulk_parameters)
         if "rows" in self._result:
+            if "col_types" in self._result:
+                col_types = self._result["col_types"]
+                tmp_data = self._result["rows"]
+
+                rows_to_convert = self._get_rows_to_convert_to_date(col_types)
+                tmp_data = self._convert_dates_to_datetime(tmp_data, rows_to_convert)
+
+                self._result["rows"] = tmp_data
+
             self.rows = iter(self._result["rows"])
 
+    @staticmethod
+    def _get_rows_to_convert_to_date(col_types):
+        return [True if col_type == 11 or col_type == 15 else False for col_type in col_types]
+
+    @staticmethod
+    def _date_to_datetime(row, rows_to_convert):
+        return list(
+            map(lambda x, y:
+                datetime.fromtimestamp(float(str(x)[0:10])) if y else x,
+                row,
+                rows_to_convert))
+
+    def _convert_dates_to_datetime(self, rows, rows_to_convert):
+        return list(
+            map(lambda x:
+                self._date_to_datetime(x, rows_to_convert),
+                rows))
+
     def executemany(self, sql, seq_of_parameters):
         """
         Prepare a database operation (query or command) and then execute it