Update app.py

app.py

@@ -1,21 +1,31 @@
 import gradio as gr
 from datasets import load_dataset
-from itertools import islice
 
-def stream_test(n=50):
+def peek_schema():
     try:
         ds = load_dataset("MultimodalUniverse/jwst", split="train", streaming=True)
-        count = sum(1 for _ in islice(ds, int(n)))
-        return f"OK. Streamed {count} JWST records without downloading the full dataset."
+        first = next(iter(ds))
+        keys = list(first.keys())
+        types = {k: type(first[k]).__name__ for k in keys}
+        # show a few short text snippets if present
+        previews = {}
+        for k, v in first.items():
+            if isinstance(v, str) and len(v) > 0:
+                previews[k] = v[:200]
+        return {
+            "keys": keys,
+            "types": types,
+            "sample_text_preview": previews
+        }
     except Exception as e:
-        return f"Error: {e}"
+        return {"error": str(e)}
 
 demo = gr.Interface(
-    fn=stream_test,
-    inputs=gr.Slider(minimum=1, maximum=200, value=50, step=1, label="How many records to stream"),
-    outputs="text",
-    title="JWST streaming check",
-    description="Test that we can stream data from the JWST dataset in small batches."
+    fn=peek_schema,
+    inputs=None,
+    outputs="json",
+    title="JWST dataset schema peek",
+    description="Streams the first record from the JWST dataset to show available fields."
 )
 
 demo.launch()