Create data_prep.py

data_prep.py

@@ -0,0 +1,25 @@
+import json
+from pathlib import Path
+
+def chunk_text(text: str, chunk_size=500, overlap=50):
+    """Split text into overlapping word chunks."""
+    words = text.split()
+    for i in range(0, len(words), chunk_size - overlap):
+        yield " ".join(words[i:i+chunk_size])
+
+def split_to_jsonl(input_file: str, output_file: str = "pretrain.jsonl",
+                   chunk_size=500, overlap=50):
+    """Split raw file into JSONL for pretraining (no cleaning)."""
+    raw_text = Path(input_file).read_text(encoding="utf-8")
+
+    with open(output_file, "w", encoding="utf-8") as f:
+        for chunk in chunk_text(raw_text, chunk_size, overlap):
+            record = {"text": chunk}
+            f.write(json.dumps(record, ensure_ascii=False) + "\n")
+
+    print(f"✅ Saved dataset → {output_file}")
+
+if __name__ == "__main__":
+    # Example usage
+    input_file = "gist.md"   # your markdown/text file
+    split_to_jsonl(input_file, "pretrain.jsonl", chunk_size=500, overlap=50)