Add test for unicode, parametrize for chunksize.

1 files changed, 15 insertions, 5 deletions

diff --git a/numpy/lib/tests/test_loadtxt.py b/numpy/lib/tests/test_loadtxt.py
index 5870915ae..5a34267ed 100644
--- a/numpy/lib/tests/test_loadtxt.py
+++ b/numpy/lib/tests/test_loadtxt.py
@@ -928,16 +928,26 @@ def test_control_character_newline_raises(nl):
         np.loadtxt(txt, quotechar=nl)
 
 
-def test_datetime_parametric_unit_discovery():
+@pytest.mark.parametrize(
+    ("generic_data", "long_datum", "unitless_dtype", "expected_dtype"),
+    [
+        ("2012-03", "2013-01-15", "M8", "M8[D]"),  # Datetimes
+        ("spam-a-lot", "tis_but_a_scratch", "U", "U17"),  # str
+    ],
+)
+@pytest.mark.parametrize("nrows", (10, 50000, 60000))  # lt, eq, gt chunksize
+def test_datetime_parametric_unit_discovery(
+    generic_data, long_datum, unitless_dtype, expected_dtype, nrows
+):
     """Check that the correct unit (e.g. month, day, second) is discovered from
     the data when a user specifies a unitless datetime."""
     # Unit should be "D" (days) due to last entry
-    data = ["2012-03"] * 50000 + ["2013-01-15"]
-    expected = np.array(data, dtype="M8[D]")
+    data = [generic_data] * 50000 + [long_datum]
+    expected = np.array(data, dtype=expected_dtype)
 
     # file-like path
     txt = StringIO("\n".join(data))
-    a = np.loadtxt(txt, dtype="M8")
+    a = np.loadtxt(txt, dtype=unitless_dtype)
     assert a.dtype == expected.dtype
     assert_equal(a, expected)
 
@@ -945,6 +955,6 @@ def test_datetime_parametric_unit_discovery():
     fd, fname = mkstemp()
     with open(fname, "w") as fh:
         fh.write("\n".join(data))
-    a = np.loadtxt(fname, dtype="M8")
+    a = np.loadtxt(fname, dtype=unitless_dtype)
     assert a.dtype == expected.dtype
     assert_equal(a, expected)