Feat: add to_json (#3743)

src/accelerate/parallelism_config.py

@@ -80,6 +80,19 @@ class ParallelismConfig:
             f"\tcp_handler={self.cp_handler})\n"
         )
 
+    def to_json(self):
+        import copy
+
+        _non_serializable_fields = ["device_mesh"]
+
+        copy.deepcopy(
+            {
+                k: copy.deepcopy(v.__dict__) if hasattr(v, "__dict__") else v
+                for k, v in self.__dict__.items()
+                if k not in _non_serializable_fields
+            }
+        )
+
     @property
     def dp_dim_names(self):
         """Names of enabled dimensions across which data parallelism is applied."""