Redirection problem

[CSUIDL PROGRAMMEr]

I am new to python. so be patient with me

I am trying to redirect the output of os.popen command to a file. I
want to append to that file. but instead of appending. The file only
shows last command that was writtenn to  it.



 filehandle= open("/root/yhpc-2.0/installer/yhpc-log" ,"a+");
    filehandle.write(" Command executed is " + cmd);
    try:
      pipe= os.popen('%s > /root/yhpc-2.0/installer/yhpc-log' %cmd );
    except : IOError;
  filehandle.close();


Any  suggestion would help.



    filehandle.close();