Unit Test: Construction of DataFrame works with empty list but not empty array

pandas/core/internals/construction.py

@@ -326,7 +326,8 @@ def ndarray_to_mgr(
     else:
         # by definition an array here
         # the dtypes will be coerced to a single dtype
-        values = _prep_ndarray(values, copy=copy_on_sanitize)
+        values = _prep_ndarray(values, columns, copy=copy_on_sanitize)
+    # values = values
 
     if dtype is not None and not is_dtype_equal(values.dtype, dtype):
         # GH#40110 see similar check inside sanitize_array
@@ -537,7 +538,7 @@ def treat_as_nested(data) -> bool:
 # ---------------------------------------------------------------------
 
 
-def _prep_ndarray(values, copy: bool = True) -> np.ndarray:
+def _prep_ndarray(values, columns, copy: bool = True) -> np.ndarray:
     if isinstance(values, TimedeltaArray) or (
         isinstance(values, DatetimeArray) and values.tz is None
     ):
@@ -577,7 +578,10 @@ def convert(v):
         values = np.array(values, copy=copy)
 
     if values.ndim == 1:
-        values = values.reshape((values.shape[0], 1))
+        if len(values) == 0 and columns is not None:
+            values = values.reshape((0, len(columns)))
+        else:
+            values = values.reshape((values.shape[0], 1))
     elif values.ndim != 2:
         raise ValueError(f"Must pass 2-d input. shape={values.shape}")
 

pandas/tests/frame/test_constructors.py

@@ -621,11 +621,6 @@ def test_constructor_2d_index(self):
         tm.assert_frame_equal(df, expected)
 
     def test_constructor_error_msgs(self):
-        msg = "Empty data passed with indices specified."
-        # passing an empty array with columns specified.
-        with pytest.raises(ValueError, match=msg):
-            DataFrame(np.empty(0), columns=list("abc"))
-
         msg = "Mixing dicts with non-Series may lead to ambiguous ordering."
         # mix dict and array, wrong size
         with pytest.raises(ValueError, match=msg):
@@ -3086,3 +3081,10 @@ def test_tzaware_data_tznaive_dtype(self, constructor):
 
         assert np.all(result.dtypes == "M8[ns]")
         assert np.all(result == ts_naive)
+
+    @pytest.mark.parametrize("data", [[], np.array([])])
+    def test_construction_empty_dataframe(self, data):
+        # GH#46822
+        result = DataFrame(data=data, columns=["a", "b"])
+        assert list(result.values) == []
+        tm.assert_index_equal(result.columns, Index(["a", "b"]))