Two comments --

since sys.argv[1] is now used twice in the script (and in any case I wrote it badly in the first place), please set a variable to the value at the top, and then reuse the variable down here.  I guess something like 'seqfile = sys.argv[1]'.

second, you don't need to create a dict and then populate it and then dump it.  Just do

dump(seqfile, fp)
dump(names, fp)

following which you can do

seqfile = load(fp)
names = load(fp)

This also eliminates the use of 'get' below...