ex16.py

# "Reading and Writing Files"
# x.open(), x.close(), x.read(), 
# x.readline() - reads just one line of a text file
# x.truncate, x.write('stuff')
# file modes 'w' (write) , 'r' (read) , 'a' (append)

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')

# truncating is pointless in 'w' mode, it will be overwritten anyway
# 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."

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

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