[Tutor] Tab delimited question

[Ben Ganzfried]

I'm searching line by line for certain tags and then printing the tag
followed by the word immediately following the tag.

So for example, suppose I had the following line of text in a file:
"this	is	a	key	test123	noise	 noise	noise 	noise 	noise"

In this example, I would want to print "key test123" to a new file.
The rest of the words I would not want.

Here is my code so far:

def test(infile, outfile):
  for line in infile:
            tagIndex = line.find("key")
            start = tagIndex + 4
            stop = line[start:].find("\t") -1
            if tagIndex != -1:
                print("start is: ", start)
                print("stop is: ", stop)
                print("spliced word is ", line[start: stop])

My question is the following: What is wrong w/ the variable 'stop'?
The index it gives me when I print out 'stop' is not even close to the
right number.  Furthermore, when I try to print out just the word
following the tag w/ the form: line[start: stop], it prints nothing
(it seems b/c my stop variable is incorrect).

I would greatly appreciate any help you have.  This is a much
simplified example from the script I'm actually writing, but I need to
figure out a way to eliminate the noise after the key and the word
immediately following it are found.

Thank you very much for any help you can provide.

Ben