Remove trailing whitespace.
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 8111fa3..74fca8a 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -368,7 +368,7 @@
    is returned. Availability: Unix, Windows.
 
    .. deprecated:: 2.6
-      This function is obsolete.  Use the :mod:`subprocess` module.  Check 
+      This function is obsolete.  Use the :mod:`subprocess` module.  Check
       especially the :ref:`subprocess-replacements` section.
 
    .. versionchanged:: 2.0
@@ -418,7 +418,7 @@
    child_stdout)``.
 
    .. deprecated:: 2.6
-      This function is obsolete.  Use the :mod:`subprocess` module.  Check 
+      This function is obsolete.  Use the :mod:`subprocess` module.  Check
       especially the :ref:`subprocess-replacements` section.
 
    Availability: Unix, Windows.
@@ -432,7 +432,7 @@
    child_stdout, child_stderr)``.
 
    .. deprecated:: 2.6
-      This function is obsolete.  Use the :mod:`subprocess` module.  Check 
+      This function is obsolete.  Use the :mod:`subprocess` module.  Check
       especially the :ref:`subprocess-replacements` section.
 
    Availability: Unix, Windows.
@@ -446,7 +446,7 @@
    child_stdout_and_stderr)``.
 
    .. deprecated:: 2.6
-      This function is obsolete.  Use the :mod:`subprocess` module.  Check 
+      This function is obsolete.  Use the :mod:`subprocess` module.  Check
       especially the :ref:`subprocess-replacements` section.
 
    Availability: Unix, Windows.
@@ -1449,7 +1449,7 @@
    These functions all execute a new program, replacing the current process; they
    do not return.  On Unix, the new executable is loaded into the current process,
    and will have the same process id as the caller.  Errors will be reported as
-   :exc:`OSError` exceptions.  
+   :exc:`OSError` exceptions.
 
    The current process is replaced immediately. Open file objects and
    descriptors are not flushed, so if there may be data buffered
@@ -1481,7 +1481,7 @@
    used to define the environment variables for the new process (these are used
    instead of the current process' environment); the functions :func:`execl`,
    :func:`execlp`, :func:`execv`, and :func:`execvp` all cause the new process to
-   inherit the environment of the current process. 
+   inherit the environment of the current process.
 
    Availability: Unix, Windows.
 
@@ -1718,7 +1718,7 @@
 
    (Note that the :mod:`subprocess` module provides more powerful facilities for
    spawning new processes and retrieving their results; using that module is
-   preferable to using these functions.  Check specially the *Replacing Older 
+   preferable to using these functions.  Check specially the *Replacing Older
    Functions with the subprocess Module* section in that documentation page.)
 
    If *mode* is :const:`P_NOWAIT`, this function returns the process id of the new