[v1] add data converter (#9263)

src/llamafactory/v1/plugins/data_plugins/converter.py

@@ -0,0 +1,71 @@
+# Copyright 2025 the LlamaFactory team.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from typing import Callable, NotRequired, TypedDict
+
+from ...extras.types import Sample, SFTSample
+
+
+class AlpacaSample(TypedDict, total=False):
+    system: NotRequired[str]
+    instruction: NotRequired[str]
+    input: NotRequired[str]
+    output: NotRequired[str]
+
+
+def alpaca_converter(raw_sample: AlpacaSample) -> SFTSample:
+    """Convert Alpaca sample to SFT sample.
+
+    Args:
+        raw_sample (AlpacaSample): Alpaca sample.
+
+    Returns:
+        SFTSample: SFT sample.
+    """
+    messages = []
+    if "system" in raw_sample:
+        messages.append(
+            {"role": "system", "content": [{"type": "text", "value": raw_sample["system"]}], "loss_weight": 0.0}
+        )
+
+    if "instruction" in raw_sample or "input" in raw_sample:
+        messages.append(
+            {
+                "role": "user",
+                "content": [
+                    {"type": "text", "value": raw_sample.get("instruction", "") + raw_sample.get("input", "")}
+                ],
+                "loss_weight": 0.0,
+            }
+        )
+
+    if "output" in raw_sample:
+        messages.append(
+            {"role": "assistant", "content": [{"type": "text", "value": raw_sample["output"]}], "loss_weight": 1.0}
+        )
+
+    return {"messages": messages}
+
+
+CONVERTERS = {
+    "alpaca": alpaca_converter,
+}
+
+
+def get_converter(converter_name: str) -> Callable[[dict], Sample]:
+    if converter_name not in CONVERTERS:
+        raise ValueError(f"Converter {converter_name} not found.")
+
+    return CONVERTERS[converter_name]