Search text file and insert line

Question

What I want to do is (using the text below as an example), search for the string “Text2” in a text file, and then insert a line (“Inserted Text”) two lines after \"Text 2\".

Answer 1

The quick-n-dirty way would be something like that

before=-1
for line in fileinput.input('file.txt', inplace=1,backup='.bak'):
    if line.startswith('Text 2'):
        before = 2
    if before == 0
        print "Inserted Text"
    if before > -1
        before = before - 1
    print line,