import sys
def unix2dos(fname):

dst_fname = fname + '.txt'
src_fobj = open(fname)
dst_fobj = open(dst_fname, 'w')
for line in src_fobj:
      line  = line.rstrip(line) + '\r\n'
      dst_fobj.write(line)
src_fobj.close()
dst_fobj.close()

if name == ‘main‘:
unix2dos(sys.argv[1])