Question

I am giving a text file with the format below:

3     Bham    Hoover - Vestiva 
123 234 1 456 876 1 876 745 1
0
4     Bham    Vestiva - Greensprings
235 876 1 647 987 1 098 765 1 234 546 1
0

This goes on for several more lines, but I am trying to convert this format to the following:

Event
Disconnect branch from bus 123 to 234 circuit 1
Disconnect branch from bus 456 to 876 circuit 1
Disconnect branch from bus 876 to 745 circuit 1
end
Event 
Disconnect branch from bus 235 to 876 circuit 1
Disconnect branch from bus 647 to 987 circuit 1
Disconnect branch from bus 098 to 765 circuit 1
Disconnect branch from bus 234 to 546 circuit 1
end

Answer 1

from itertools import islice
with open('file.txt', 'r') as f:
    # iterate over every 3rd line, starting with the 2nd
    for line in islice(f, 1, None, 3):
        parts = line.split()
        print 'Event'
        # iterate over 3-element chunks
        for x in zip(*(iter(parts),) * 3):
            print 'Disconnect branch from bus %s to %s circuit %s' % x
        print 'end'

Output:

Event
Disconnect branch from bus 123 to 234 circuit 1
Disconnect branch from bus 456 to 876 circuit 1
Disconnect branch from bus 876 to 745 circuit 1
end
Event
Disconnect branch from bus 235 to 876 circuit 1
Disconnect branch from bus 647 to 987 circuit 1
Disconnect branch from bus 098 to 765 circuit 1
Disconnect branch from bus 234 to 546 circuit 1
end

Credits to the chunking code go to Iteration over list slices