feat(py): Allow gguf duplicate keys if they match by value and type

This is helpful for hybrid models that want to do gguf param setting by
calling multiple parent classes without needing to make those parent
classes try/except on every attempt to set a gguf value.

Branch: GraniteFour

Signed-off-by: Gabe Goodhart <[email protected]>

Author: gabe-l-hart

gguf-py/gguf/gguf_writer.py

@@ -270,7 +270,14 @@ def write_ti_data_to_file(self) -> None:
         self.state = WriterState.TI_DATA
 
     def add_key_value(self, key: str, val: Any, vtype: GGUFValueType, sub_type: GGUFValueType | None = None) -> None:
-        if any(key in kv_data for kv_data in self.kv_data):
+        # Disallow duplicate keys if they differ by value or type
+        if any(
+            (
+                key in kv_data and
+                (kv_data[key].value != val or kv_data[key].type != vtype)
+            )
+            for kv_data in self.kv_data
+        ):
             raise ValueError(f'Duplicated key name {key!r}')
 
         self.kv_data[0][key] = GGUFValue(value=val, type=vtype, sub_type=sub_type)