use strip() instead of lstrip() in remove_whitespace filter (#3408)

Author: ziqing-huang

lm_eval/filters/extraction.py

@@ -105,13 +105,13 @@ def filter_set(inst):
 
 @register_filter("remove_whitespace")
 class WhitespaceFilter(Filter):
-    """Filters out leading whitespace from responses."""
+    """Filters out leading and trailing whitespace from responses."""
 
     def apply(self, resps: list[list[str]], docs: list[dict]) -> list[list[str]]:
         def filter_set(inst):
             filtered_resp = []
             for resp in inst:
-                resp = resp.lstrip()
+                resp = resp.strip()
                 filtered_resp.append(resp)
             return filtered_resp