Support saving numpy predictions to remote FS (#2245)

#2245

ludwig/data/postprocessing.py

@@ -24,6 +24,7 @@
 from ludwig.data.utils import convert_to_dict
 from ludwig.utils.data_utils import DATAFRAME_FORMATS, DICT_FORMATS
 from ludwig.utils.dataframe_utils import to_numpy_dataset
+from ludwig.utils.fs_utils import has_remote_protocol, open_file
 from ludwig.utils.misc_utils import get_from_registry
 from ludwig.utils.strings_utils import make_safe_filename
 
@@ -66,7 +67,11 @@ def _save_as_numpy(predictions, output_directory, saved_keys, backend):
     for k, v in numpy_predictions.items():
         k = k.replace("<", "[").replace(">", "]")  # Replace <UNK> and <PAD> with [UNK], [PAD]
         if k not in saved_keys:
-            np.save(npy_filename.format(make_safe_filename(k)), v)
+            if has_remote_protocol(output_directory):
+                with open_file(npy_filename.format(make_safe_filename(k)), mode="wb") as f:
+                    np.save(f, v)
+            else:
+                np.save(npy_filename.format(make_safe_filename(k)), v)
             saved_keys.add(k)