str.join() doesn't convert arguments anymore.

Doc/library/stdtypes.rst

@@ -897,11 +897,10 @@ functions based on regular expressions.
 
 .. method:: str.join(seq)
 
-   Return a string which is the concatenation of the values in the sequence
-   *seq*. Non-string values in *seq* will be converted to a string using their
-   respective ``str()`` value.  If there are any :class:`bytes` objects in
-   *seq*, a :exc:`TypeError` will be raised.  The separator between elements is
-   the string providing this method.
+   Return a string which is the concatenation of the strings in the sequence
+   *seq*.  A :exc:`TypeError` will be raised if there are any non-string values
+   in *seq*, including :class:`bytes` objects.  The separator between elements
+   is the string providing this method.
 
 
 .. method:: str.ljust(width[, fillchar])