fix(serializer): NaN handling (#1107)

Author: hassiebp

langfuse/serializer.py

@@ -1,6 +1,7 @@
 """@private"""
 
 import enum
+import math
 from asyncio import Queue
 from collections.abc import Sequence
 from dataclasses import asdict, is_dataclass
@@ -54,6 +55,9 @@ def default(self, obj: Any):
             if np is not None and isinstance(obj, np.generic):
                 return obj.item()
 
+            if isinstance(obj, float) and math.isnan(obj):
+                return None
+
             if isinstance(obj, (Exception, KeyboardInterrupt)):
                 return f"{type(obj).__name__}: {str(obj)}"