Append and Truncating together in Python
Question: So, I am at exercise 16 of Zed Shaw's Python book.

I thought of trying out both append and truncate on the same file. I know,
this does not make sense. But, I am new and I am trying to learn what would
happen if I used both.

So, first I am opening the file in append mode and then truncating it and then
writing into it.

But, the truncate is not working here and whatever I write gets appended to
the file.

So, can someone kindly explain why the truncate would not work ? Even though I
am opening the file in append mode first, I believe I am calling the truncate
function after that and it should have worked !!!

Following is my code:

    
    
    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, 'a')
    
    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 + "\n" + line2 + "\n" + line3)
    
    print "And finally, we close it."
    target.close()
    


Answer: The argument `'a'` opens the file for appending. You will need to use `'w'`
instead.

