Pythonic Way Of Inserting Lines To A File

So as the description describes, I would like to add text to a file in a sequential manner. Say, for example I have a file like this (NOT HTML, this is just an imaginary language)

Solution 1:

I would do it like this:

with open(outputfile,'w') asout, open(inputfile) as f:
    for line in f:
        out.write(line)
        if tag_match(line):  #Somehow determine ifthis line is a match where we want to insert text.
           out.write('\n'.join(fruits)+'\n')

You might come up with a way to make it faster, but I doubt it is worthwhile. This is simple, easy to read, and gets the job done. "pythonic" enough for me :-)

Solution 2:

The most pythonic way for parsing markup is to use a suitable module to parse it.