ex16.py

from sys import argv

script, filename = argv

print("We're going to erase %r." % filename)
print("If you don't want that, hit CTRL-C (^C).")
print("If you do want that, hit RETURN.")

raw_input("?")

print "Opening the file..."
target = open(filename, 'w')

print "Truncating the file. Goodbye!"
target.truncate()

print "Now I'm going to ask you for three lines."

line1 = raw_input("line 1: ")
line2 = raw_input("line 2: ")
line3 = raw_input("line 3: ")

print("I'm going to write these to the file.")

line = "%s\n%s\n%s\n" % (line1, line2, line3)
target.write(line)

target.write(line1)
target.write('\n')
target.write(line2)
target.write("\n")
target.write(line3)
target.write("\n")

print("And finally, we close it.")
target.close()