use is_homogeneous_type

Author: jbrockmendel

pandas/core/generic.py

@@ -727,7 +727,7 @@ def transpose(self, *args, **kwargs):
         nv.validate_transpose(tuple(), kwargs)
         result = self._constructor(new_values, **new_axes).__finalize__(self)
 
-        if len(self.columns) and (self.dtypes == self.dtypes.iloc[0]).all():
+        if self.ndim == 2 and self._is_homogeneous_type:
             # FIXME: self.dtypes[0] can fail in tests
             if is_extension_array_dtype(self.dtypes.iloc[0]):
                 # Retain ExtensionArray dtypes through transpose;