Document preferred method for attribute setting (#2712)

open-telemetry · May 25, 2022 · 709afdd · 709afdd
1 parent 8200f45
commit 709afdd
Showing 1 changed file with 8 additions and 2 deletions.
diff --git a/opentelemetry-api/src/opentelemetry/trace/span.py b/opentelemetry-api/src/opentelemetry/trace/span.py
@@ -86,7 +86,10 @@ def set_attributes(
 
         Sets Attributes with the key and value passed as arguments dict.
 
-        Note: The behavior of `None` value attributes is undefined, and hence strongly discouraged.
+        Note: The behavior of `None` value attributes is undefined, and hence
+        strongly discouraged. It is also preferred to set attributes at span
+        creation, instead of calling this method later since samplers can only
+        consider information already present during span creation.
         """
 
     @abc.abstractmethod
@@ -95,7 +98,10 @@ def set_attribute(self, key: str, value: types.AttributeValue) -> None:
 
         Sets a single Attribute with the key and value passed as arguments.
 
-        Note: The behavior of `None` value attributes is undefined, and hence strongly discouraged.
+        Note: The behavior of `None` value attributes is undefined, and hence
+        strongly discouraged. It is also preferred to set attributes at span
+        creation, instead of calling this method later since samplers can only
+        consider information already present during span creation.
         """
 
     @abc.abstractmethod