added float conversion for field keys

cbutil/data_points.py

@@ -35,7 +35,7 @@ def data_point_factory(run, *,
     if tag_keys is None and no_tag_keys is None:
         raise ValueError("You need either specify tag_keys or no_tag_keys")
 
-    fields = {key: run[key] for key in field_keys}
+    fields = {key: float(run[key]) for key in field_keys}
 
     if tag_keys is None:
         tag_keys = run.keys() - no_tag_keys - field_keys - {time_key}