Need help in extracting lines from word using python

[razinzamada at gmail.com]

I'm currently trying to extract some data between 2 lines of an input file using Python. the infile is set up such that there is a line -START- where I need the next 10 lines of code if and only if the -END- condition occurs before the next -START-. The -START- line occurs many times before the -END-. Heres a general example of what I mean:

blah
blah
-START-
10 lines I DONT need
blah
-START-
10 lines I need
blah
blah
-END-
blah
blah
-START-
10 lines I dont need
blah
-START-

.... and so on and so forth

so far I have only been able to get the -START- + 10 lines for every iteration, but am at a total loss when it comes to specifying the condition to only write if the -END- condition comes before another -START- condition. I'm a bit of a newb, so any help will be greatly appreciated.


heres the code I have for printing the -START- + 10 lines:

    in = open('input.log')
    out = open('output.txt', 'a')

    lines = in.readlines()
        for i, line in enumerate(lines):
            if (line.find('START')) > -1:
                out.write(line)
                out.write(lines[i + 1])
                out.write(lines[i + 2])
                out.write(lines[i + 3])
                out.write(lines[i + 4])
                out.write(lines[i + 5])
                out.write(lines[i + 6])
                out.write(lines[i + 7])
                out.write(lines[i + 8])
                out.write(lines[i + 9])
                out.write(lines[i + 10])