Writing to a file in Python

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 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."

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

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

ex16_extra_credit.py

# LPTHW Exercise 16

# Import the argv variable from the sys module
from sys import argv

#unpack the contents of argv into script and filename
script, filename = argv

#create a general variable which we will re-use for the prompt
prompt = "line %d: "

# Tell the user that we are going to erase the filename they mentioned in the cmd argument
print "We're going to erase %r." % filename
# Prompt the user that they can hit CTEL-C if they do not want to erase the file
print "If you don't want that, hit CTRL-C (^C)."
#Prompt the user that they can hit RETURN if they DO want to erase the file
print "If you want that hit RETURN."

# Take input from the user... this will determine if we will erase the file or not
raw_input("?")


print "Opening the file..."
#open the specified file and hold the fp in a variable called target
target = open(filename, 'w')

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

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

#aAccept three lined from the user
line1 = raw_input(prompt % 1)
line2 = raw_input(prompt % 2)
line3 = raw_input(prompt % 3)

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

#Write all the three lines to the file seperated with a newline
target.write(line1)
target.write("\n")
target.write(line2)
target.write("\n")
target.write(line3)
target.write("\n")

print "And we finally, close it."
# Close the file
target.close()

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