Getting last line of each line occurrence in a file

[deanhystad]

Your logic is backward. You should present results when you encounter a start, not an end. It is omly when you see START, or run out of lines, that you know you found the last end.

with open('data.txt', 'r') as file:
    start = end = None
    for line in map(str.strip, file):
        if 'TEST Started' in line:
            if end:
                # Print previous start/end pair
                print(start, end, sep="\n", end="\n\n")
            start = line
            end = None
        elif 'TEST end' in line:
            end = line
    if start and end:
        print(start, end, sep="\n")