FIX-modin-project#6778: Read parquet files without file extensions us…

…ing fastparquet

In supporting fastparquet, modin takes the paths provided, globs them,
and filters them to only look at files with the .parq or .parquet
extension. This commit adds support so that if the path supplied is
explicitly a file, it will be included.

Signed-off by: Ari Brown <[email protected]>

modin/core/io/column_stores/parquet_dispatcher.py

@@ -285,19 +285,33 @@ def files(self):
     def to_pandas_dataframe(self, columns):
         return self.dataset.to_pandas(columns=columns)
 
+    # Karthik Velayutham writes:
+    #
+    # fastparquet doesn't have a nice method like PyArrow, so we
+    # have to copy some of their logic here while we work on getting
+    # an easier method to get a list of valid files.
+    # See: https://github.com/dask/fastparquet/issues/795
     def _get_fastparquet_files(self):  # noqa: GL08
-        # fastparquet doesn't have a nice method like PyArrow, so we
-        # have to copy some of their logic here while we work on getting
-        # an easier method to get a list of valid files.
-        # See: https://github.com/dask/fastparquet/issues/795
         if "*" in self.path:
             files = self.fs.glob(self.path)
         else:
-            files = [
-                f
-                for f in self.fs.find(self.path)
-                if f.endswith(".parquet") or f.endswith(".parq")
-            ]
+            # (Resolving issue #6778)
+            #
+            # Users will pass in a directory to a delta table, which stores parquet
+            # files in various directories along with other, non-parquet files. We
+            # need to identify those parquet files and not the non-parquet files.
+            #
+            # However, we also need to support users passing in explicit files that
+            # don't necessarily have the `.parq` or `.parquet` extension -- if a user
+            # says that a file is parquet, then we should probably give it a shot.
+            if os.path.isfile(self.path):
+                files = self.fs.find(self.path)
+            else:
+                files = [
+                    f
+                    for f in self.fs.find(self.path)
+                    if f.endswith(".parquet") or f.endswith(".parq")
+                ]
         return files
 
 

modin/pandas/test/test_io.py

@@ -1464,6 +1464,20 @@ def comparator(df1, df2):
                 comparator=comparator,
             )
 
+    # Tests issue #6778
+    def test_read_parquet_no_extension(self, engine, make_parquet_file):
+        with ensure_clean(".parquet") as unique_filename:
+            # Remove the .parquet extension
+            no_ext_fname = unique_filename[:unique_filename.index(".parquet")]
+
+            make_parquet_file(filename=no_ext_fname)
+            eval_io(
+                fn_name="read_parquet",
+                # read_parquet kwargs
+                engine=engine,
+                path=no_ext_fname
+            )
+
     @pytest.mark.parametrize(
         "filters",
         [None, [], [("col1", "==", 5)], [("col1", "<=", 215), ("col2", ">=", 35)]],