cleanup

Author: jbrockmendel

pandas/core/dtypes/cast.py

@@ -352,6 +352,7 @@ def maybe_promote(dtype, fill_value=np.nan):
             # We treat string-like dtypes as object, and _always_ fill
             #  with np.nan
             fill_value = np.nan
+            dtype = np.dtype(np.object_)
 
     # returns tuple of (dtype, fill_value)
     if issubclass(dtype.type, np.datetime64):
@@ -424,8 +425,6 @@ def maybe_promote(dtype, fill_value=np.nan):
     # in case we have a string that looked like a number
     if is_extension_array_dtype(dtype):
         pass
-    elif is_datetime64tz_dtype(dtype):
-        pass
     elif issubclass(np.dtype(dtype).type, (bytes, str)):
         dtype = np.object_
 

pandas/tests/dtypes/cast/test_promote.py

@@ -332,18 +332,17 @@ def test_maybe_promote_any_with_datetime64(
     dtype = np.dtype(any_numpy_dtype_reduced)
     boxed, box_dtype = box  # read from parametrized fixture
 
-    if is_datetime64_dtype(dtype):
-        if boxed and (
-            box_dtype == object
-            or (box_dtype is None and not is_datetime64_dtype(type(fill_value)))
-        ):
-            pytest.xfail("falsely upcasts to object")
-    else:
-        if boxed and (
-            box_dtype == "dt_dtype"
-            or (box_dtype is None and is_datetime64_dtype(type(fill_value)))
-        ):
-            pytest.xfail("mix of lack of upcasting, resp. wrong missing value")
+    if boxed:
+        if is_datetime64_dtype(dtype):
+            if box_dtype == object:
+                pytest.xfail("falsely upcasts to object")
+            elif box_dtype is None and not is_datetime64_dtype(type(fill_value)):
+                pytest.xfail("falsely upcasts to object")
+        else:
+            if box_dtype == "dt_dtype":
+                pytest.xfail("mix of lack of upcasting, resp. wrong missing value")
+            elif box_dtype is None and is_datetime64_dtype(type(fill_value)):
+                pytest.xfail("mix of lack of upcasting, resp. wrong missing value")
 
     # special case for box_dtype
     box_dtype = np.dtype(datetime64_dtype) if box_dtype == "dt_dtype" else box_dtype