Address review comments and fix util for non-local paths and non-exis…

…tent local paths

Signed-off-by: Rehan Durrani <[email protected]>

modin/core/execution/ray/implementations/pandas_on_ray/io/io.py

@@ -169,7 +169,7 @@ def to_csv(cls, qc, **kwargs):
         if len(ray.nodes()) > 1 and is_local_path(kwargs["path_or_buf"]):
             raise ValueError(
                 "`path_or_buf` must point to a networked file or buffer when in cluster mode."
-            )        
+            )
 
         signals = SignalActor.remote(len(qc._modin_frame._partitions) + 1)
 
@@ -286,7 +286,7 @@ def to_parquet(cls, qc, **kwargs):
         if len(ray.nodes()) > 1 and is_local_path(kwargs["path_or_buf"]):
             raise ValueError(
                 "`path_or_buf` must point to a networked file or buffer when in cluster mode."
-            )        
+            )
 
         def func(df, **kw):
             """

modin/core/io/utils.py

@@ -16,6 +16,7 @@
 import os
 import pathlib
 import re
+from typing import Union
 
 S3_ADDRESS_REGEX = re.compile("[sS]3://(.*?)/(.*)")
 
@@ -37,5 +38,38 @@ def is_local_path(path_or_buf) -> bool:
         if S3_ADDRESS_REGEX.match(path_or_buf) is not None or "://" in path_or_buf:
             return False  # S3 or network path.
     if isinstance(path_or_buf, (str, pathlib.PurePath)):
-        return os.path.exists(path_or_buf)
+        if os.path.exists(path_or_buf):
+            return True
+        local_device_id = os.stat(os.getcwd()).st_dev
+        path_device_id = get_device_id(path_or_buf)
+        if path_device_id == local_device_id:
+            return True
     return False
+
+
+def get_device_id(path: Union[str, pathlib.PurePath]) -> Union[int, None]:
+    """
+    Return the result of `os.stat(path).st_dev` for the portion of `path` that exists locally.
+
+    Parameters
+    ----------
+    path : str, path object
+        The path to check.
+
+    Returns
+    -------
+    The `st_dev` field of `os.stat` of the portion of the `path` that exists locally, None if no
+    part of the path exists locally.
+    """
+    index = 1
+    path_list = list(pathlib.Path(path).parts)
+    if path_list[0] == "/":
+        index += 1
+    try:
+        os.stat(os.path.join(*path_list[:index]))
+    except:
+        return None
+    while os.path.exists(os.path.join(*path_list[:index])):
+        index += 1
+    index -= 1
+    return os.stat(os.path.join(*path_list[:index])).st_dev