append one file to another

[b83503104 at yahoo.com]

Hi,

I want to append one (huge) file to another (huge) file.  The current
way I'm doing it is to do something like:

infile = open (infilename, 'r')
filestr = infile.read()
outfile = open(outfilename, 'a')
outfile.write(filestr)

I wonder if there is a more efficient way doing this?
Thanks.