Remove trailing whitespace.
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index 25d5f16..86407be 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -215,7 +215,7 @@
    .. method:: close()
 
       Flush and close this stream. This method has no effect if the file is
-      already closed. Once the file is closed, any operation on the file 
+      already closed. Once the file is closed, any operation on the file
       (e.g. reading or writing) will raise an :exc:`IOError`. The internal
       file descriptor isn't closed if *closefd* was False.
 
@@ -629,7 +629,7 @@
    .. attribute:: line_buffering
 
       Whether line buffering is enabled.
-   
+
 
 .. class:: StringIO([initial_value[, encoding[, errors[, newline]]]])