finalize issue #62

monetdbe/_cffi.py

@@ -95,9 +95,9 @@ def check_error(msg: ffi.CData) -> None:
     lib.monetdbe_double: ("double", py_float, np.dtype(np.float), np.finfo(np.float).min),
     lib.monetdbe_str: ("str", make_string, np.dtype('=O'), None),
     lib.monetdbe_blob: ("blob", make_blob, np.dtype('=O'), None),
-    lib.monetdbe_date: ("date", py_date, np.dtype('datetime64[D]'), None),
-    lib.monetdbe_time: ("time", py_time, np.dtype('datetime64[ns]'), None),
-    lib.monetdbe_timestamp: ("timestamp", py_timestamp, np.dtype('datetime64[ns]'), None),
+    lib.monetdbe_date: ("date", py_date, np.dtype('=O'), None),  # np.dtype('datetime64[D]')
+    lib.monetdbe_time: ("time", py_time, np.dtype('=O'), None),  # np.dtype('datetime64[ns]')
+    lib.monetdbe_timestamp: ("timestamp", py_timestamp, np.dtype('=O'), None),  # np.dtype('datetime64[ns]')
 }
 
 
@@ -268,14 +268,11 @@ def result_fetch_numpy(self, monetdbe_result: ffi.CData):
             cast_string, cast_function, numpy_type, monetdbe_null = type_map[rcol.type]
 
             if numpy_type.char == 'O':
-                lib.PyUnicode_FromString(rcol.data)
-                char_value = ffi.cast("char *", rcol.data)
-                data = ffi.string(char_value)
-                data.decode('utf-8')
-
-            buffer_size = monetdbe_result.nrows * numpy_type.itemsize
-            c_buffer = ffi.buffer(rcol.data, buffer_size)
-            np_col: np.ndarray = np.frombuffer(c_buffer, dtype=numpy_type)
+                np_col: np.ndarray = np.array([extract(rcol, r) for r in range(monetdbe_result.nrows)])
+            else:
+                buffer_size = monetdbe_result.nrows * numpy_type.itemsize
+                c_buffer = ffi.buffer(rcol.data, buffer_size)
+                np_col = np.frombuffer(c_buffer, dtype=numpy_type)
 
             if monetdbe_null:
                 mask = np_col == monetdbe_null

monetdbe/monetize.py

@@ -50,13 +50,20 @@ def monet_memoryview(data: memoryview) -> str:
     return "'%s'" % data.tobytes().hex()
 
 
+def monet_float(data: float) -> str:
+    if data != data:  # yes this is how you can check if a float is a NaN
+        return 'NULL'
+    else:
+        return str(data)
+
+
 mapping: List[Tuple[Type, Callable]] = [
     (str, monet_escape),
     (bytes, monet_bytes),
     (memoryview, monet_memoryview),
     (int, str),
     (complex, str),
-    (float, str),
+    (float, monet_float),
     (decimal.Decimal, str),
     (datetime.datetime, monet_escape),
     (datetime.time, monet_escape),

tests/test_dataframe.py

@@ -1,7 +1,7 @@
 from datetime import datetime
 from typing import List, Any
 from unittest import TestCase
-
+from math import isnan
 from pandas import DataFrame
 
 from monetdbe import connect, Timestamp
@@ -17,9 +17,10 @@ def _connect(values: List[Any], type: str) -> DataFrame:
 
 class TestDataFrame(TestCase):
     def test_timestamp(self):
+        now = datetime.now().replace(microsecond=0)  # monetdb doesn't support microseconds
         values = [
-            datetime.now(),
-            Timestamp(2004, 2, 14, 7, 15, 0, 510241),
+            now,
+            Timestamp(2004, 2, 14, 7, 15, 0, 510000),
         ]
         df = _connect(values, 'timestamp')
         self.assertEqual(values, list(df['d']))
@@ -32,7 +33,8 @@ def test_int(self):
     def test_float(self):
         values = [5.0, 10.0, -100.0, float('nan')]
         df = _connect(values, 'float')
-        self.assertEqual(values, list(df['d']))
+        self.assertEqual(values[:-1], list(df['d'])[:-1])
+        self.assertTrue(isnan(df['d'].iloc[-1]))
 
     def test_char(self):
         values = ['a', 'i', 'é']