TST: test_cast_1d_array

Author: toobaz

pandas/tests/dtypes/test_cast.py

@@ -21,7 +21,8 @@
     infer_dtype_from_array,
     maybe_convert_string_to_object,
     maybe_convert_scalar,
-    find_common_type)
+    find_common_type,
+    construct_1d_array_from_listlike)
 from pandas.core.dtypes.dtypes import (
     CategoricalDtype,
     DatetimeTZDtype,
@@ -407,3 +408,24 @@ def test_period_dtype(self):
                        np.dtype('datetime64[ns]'), np.object, np.int64]:
             assert find_common_type([dtype, dtype2]) == np.object
             assert find_common_type([dtype2, dtype]) == np.object
+
+    @pytest.mark.parametrize('dtype', [int, float, str, object, None])
+    @pytest.mark.parametrize('datum1', [1, 2., "3", (4, 5), [6, 7], None])
+    @pytest.mark.parametrize('datum2', [8, 9., "10", (11, 12), [13, 14], None])
+    def test_cast_1d_array(self, dtype, datum1, datum2):
+        data = [datum1, datum2]
+        try:
+            # Conversion to 1d array is possible if requested dtype is object
+            possible = dtype is object
+            # ... or the following succeeds _and_ the result has dimension 1:
+            possible = possible or np.array(data, dtype=dtype).ndim == 1
+            if not possible:
+                exc = ValueError
+        except (ValueError, TypeError) as exception:
+            exc = type(exception)
+
+        if possible:
+            assert list(construct_1d_array_from_listlike(data)) == data
+        else:
+            pytest.raises(exc, construct_1d_array_from_listlike,
+                          data, dtype=dtype)