Update README.md

README.md

@@ -36,13 +36,35 @@ tags:
 <!-- Provide a quick summary of the dataset. -->
 ## Dataset Description
 
-**83,025,738 chess positions** evaluated with Stockfish at various depths and node count. Produced by, and for, the [Lichess analysis board](https://lichess.org/analysis), running various flavours of Stockfish within user browsers. This version of the dataset is a de-normalized version of [the original dataset](https://database.lichess.org/#evals) and contains **227,340,112 rows**.
+**100,731,099 chess positions** evaluated with Stockfish at various depths and node count. Produced by, and for, the [Lichess analysis board](https://lichess.org/analysis), running various flavours of Stockfish within user browsers. This version of the dataset is a de-normalized version of [the original dataset](https://database.lichess.org/#evals) and contains **276,985,422 rows**.
 
+This dataset is updated monthly, and was last updated on October 15th, 2024.
 
 
 ### Dataset Creation
-WIP
 
+```python
+from datasets import load_dataset
+
+dset = load_dataset("json", data_files="lichess_db_eval.jsonl", split="train")
+
+def batch_explode_rows(batch):
+    exploded = {"fen": [], "line": [], "depth": [], "knodes": [], "cp": [], "mate": []}
+    for fen, evals in zip(batch["fen"], batch["evals"]):
+        for eval_ in evals:
+            for pv in eval_["pvs"]:
+                exploded["fen"].append(fen)
+                exploded["line"].append(pv["line"])
+                exploded["depth"].append(eval_["depth"])
+                exploded["knodes"].append(eval_["knodes"])
+                exploded["cp"].append(pv["cp"])
+                exploded["mate"].append(pv["mate"])
+    return exploded
+
+dset = dset.map(batch_explode_rows, batched=True, batch_size=64, num_proc=12, remove_columns=dset.column_names)
+
+dset.push_to_hub("Lichess/chess-evaluations")
+```
 ### Dataset Usage
 
 Using the `datasets` library: