python 3 the hard way lesson 17

#http://learnpythonthehardway.org/book/ex17.html
#
#takes to file names
#one file in and one file out
#eg
#C:\Python33>python PTHW17.py 1.txt.txt 2.txt

from sys import argv
from os.path import exists

script, from_file, to_file =argv

print ("Copying from {} to {}".format(from_file, to_file))

#we could do this on one line but I don't know how yet

in_file = open(from_file)
indata = in_file.read()

print ("The input file is {} long".format(len(indata)))

print ("Does the output file exist? {}".format(exists(to_file)))

print ("Ready? hit RETURN to continue. ctrl - c to abort")
input()

out_file = open(to_file,'w')
out_file.write(indata)

print ("Alright, all done.")# File {} is copied to File {}".format(from_file,out_file)))

out_file.close()
in_file.close()