fix PR06 failing CI (#44773)

MarcoGorelli · web-flow · commit b7ac9bee8916 · 2021-12-05T19:56:59.000-05:00
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
@@ -1102,7 +1102,7 @@ def to_string(
         ...
 
     @Substitution(
-        header_type="bool or sequence of strings",
+        header_type="bool or sequence of str",
         header="Write out the column names. If a list of strings "
         "is given, it is assumed to be aliases for the "
         "column names",
