Update io util to convert path like object to string (#8275)

Fixes failing dask-cudf s3 test introduced from changes to `fsspec.stringify_path` in their 2021.5.0 release.

Problem description:
While reading remote files with dask-cudf the `path_or_object` param is populated with remote file objects such as `s3fs.s3File` or `gcsfs.GCSFile`. Updates to the `fsspec.stringify_path` util results in returning the string path for such objects resulting in cudf looking for those file paths locally. 

Fix:
Fix uses one of the branches from the original `stringify_path` util that checks if a `path like` object implement the `fsspath` protocol and gets the string representation from that.

Authors:
  - Ayush Dattagupta (https://github.com/ayushdg)

Approvers:
  - Keith Kraus (https://github.com/kkraus14)

URL: #8275

python/cudf/cudf/io/parquet.py

@@ -5,7 +5,6 @@
 from uuid import uuid4
 
 from fsspec.core import get_fs_token_paths
-from fsspec.utils import stringify_path
 from pyarrow import dataset as ds, parquet as pq
 
 import cudf
@@ -203,7 +202,7 @@ def read_parquet(
     for source in filepath_or_buffer:
         if ioutils.is_directory(source, **kwargs):
             fs = _ensure_filesystem(passed_filesystem=None, path=source)
-            source = stringify_path(source)
+            source = ioutils.stringify_pathlike(source)
             source = fs.sep.join([source, "*.parquet"])
 
         tmp_source, compression = ioutils.get_filepath_or_buffer(

python/cudf/cudf/utils/ioutils.py

@@ -1051,7 +1051,7 @@ def _is_local_filesystem(fs):
 def ensure_single_filepath_or_buffer(path_or_data, **kwargs):
     """Return False if `path_or_data` resolves to multiple filepaths or buffers
     """
-    path_or_data = fsspec.utils.stringify_path(path_or_data)
+    path_or_data = stringify_pathlike(path_or_data)
     if isinstance(path_or_data, str):
         storage_options = kwargs.get("storage_options")
         path_or_data = os.path.expanduser(path_or_data)
@@ -1076,7 +1076,7 @@ def ensure_single_filepath_or_buffer(path_or_data, **kwargs):
 def is_directory(path_or_data, **kwargs):
     """Returns True if the provided filepath is a directory
     """
-    path_or_data = fsspec.utils.stringify_path(path_or_data)
+    path_or_data = stringify_pathlike(path_or_data)
     if isinstance(path_or_data, str):
         storage_options = kwargs.get("storage_options")
         path_or_data = os.path.expanduser(path_or_data)
@@ -1121,7 +1121,7 @@ def get_filepath_or_buffer(
     compression : str
         Type of compression algorithm for the content
     """
-    path_or_data = fsspec.utils.stringify_path(path_or_data)
+    path_or_data = stringify_pathlike(path_or_data)
 
     if isinstance(path_or_data, str):
         storage_options = kwargs.get("storage_options")
@@ -1223,6 +1223,27 @@ def is_fsspec_open_file(file_obj):
     return False
 
 
+def stringify_pathlike(pathlike):
+    """
+    Convert any object that implements the fspath protocol
+    to a string. Leaves other objects unchanged
+    Parameters
+    ----------
+    pathlike
+        Pathlike object that implements the fspath protocol
+
+    Returns
+    -------
+    maybe_pathlike_str
+        String version of the object if possible
+    """
+    maybe_pathlike_str = (
+        pathlike.__fspath__() if hasattr(pathlike, "__fspath__") else pathlike
+    )
+
+    return maybe_pathlike_str
+
+
 def buffer_write_lines(buf, lines):
     """
     Appends lines to a buffer.