下載之後，再次執行轉換高低位元。 http://donaldknuth.blogspot.tw/2010/03/gae.html

gae_decode.py

in_file  = file('some_file','rb');
out_file = file('some_file_decode','wb');
exchange = (lambda x: chr((lambda h:(ord(h)%16)*16)(x)+(lambda l:(ord(l)/16))(x)));
in_file.seek(0,2);
counter = in_file.tell();
in_files.seek(0,0);
while counter>0:
   out_file.write(exchange(in_file.read(1)));
   counter-=1;
in_file.close();
out_file.close();