trying yet again to make work for both streaming settings

merfish.py

@@ -1,8 +1,6 @@
 import datasets
 import os
 import pandas as pd
-import pyarrow.parquet as pq
-
 
 class MERFISHConfig(datasets.BuilderConfig):
     def __init__(self, **kwargs):
@@ -11,7 +9,7 @@ class MERFISHConfig(datasets.BuilderConfig):
 
 class MERFISH(datasets.GeneratorBasedBuilder):
     BUILDER_CONFIGS = [
-        MERFISHConfig(name="raw", description="Raw MERFISH data"),
+        MERFISHConfig(name="raw", description="Raw MERFISH counts per gene"),
         MERFISHConfig(name="processed", description="Processed MERFISH data"),
     ]
 
@@ -27,20 +25,20 @@ class MERFISH(datasets.GeneratorBasedBuilder):
         )
 
     def _split_generators(self, dl_manager):
-        base_path = os.path.join(self.config.name, "expression")
+        base_path = f"{self.config.name}/expression"
 
         if dl_manager.is_streaming:
             expression_files = list(dl_manager.iter_files(base_path))
         else:
-            expression_dir = dl_manager.download_and_extract(base_path)
-            expression_files = sorted([
-                os.path.join(expression_dir, f)
-                for f in os.listdir(expression_dir)
-                if f.endswith(".parquet")
-            ])
+            # Manually list known file parts if not streaming
+            num_parts = 87  # or use Hugging Face file listings to make this dynamic
+            expression_files = [
+                f"{base_path}/part-{i:07d}.parquet" for i in range(num_parts)
+            ]
+            expression_files = dl_manager.download(expression_files)
 
-        gene_metadata = dl_manager.download(os.path.join(self.config.name, "gene_metadata.parquet"))
-        cell_metadata = dl_manager.download(os.path.join(self.config.name, "cell_metadata.parquet"))
+        gene_metadata = dl_manager.download(f"{self.config.name}/gene_metadata.parquet")
+        cell_metadata = dl_manager.download(f"{self.config.name}/cell_metadata.parquet")
 
         return [
             datasets.SplitGenerator(
@@ -56,8 +54,8 @@ class MERFISH(datasets.GeneratorBasedBuilder):
 
     def _generate_examples(self, expression_files, gene_metadata_path, cell_metadata_path, fs):
         if fs is not None:
-            gene_df = pd.read_parquet(fs.open(gene_metadata_path))
-            cell_df = pd.read_parquet(fs.open(cell_metadata_path))
+            gene_df = pd.read_parquet(fs.open(gene_metadata_path, "rb"))
+            cell_df = pd.read_parquet(fs.open(cell_metadata_path, "rb"))
         else:
             gene_df = pd.read_parquet(gene_metadata_path)
             cell_df = pd.read_parquet(cell_metadata_path)
@@ -67,8 +65,8 @@ class MERFISH(datasets.GeneratorBasedBuilder):
         idx = 0
         for filepath in expression_files:
             if fs is not None:
-                f = fs.open(filepath, "rb")
-                df = pd.read_parquet(f)
+                with fs.open(filepath, "rb") as f:
+                    df = pd.read_parquet(f)
             else:
                 df = pd.read_parquet(filepath)