import itertools
 
def resetable_counter(start):
    while True:
        for i in itertools.count(start):
            reset = yield i
            if reset:
                start = reset
                break
 
def ranges(seq):
    start, end = seq[0], seq[0]
    counter = resetable_counter(start)
    for count, item in zip(counter, seq):
        if not count == item:
            yield start, end
            start, end = item, item
            counter.send(item)
        end = item
    yield start, end
 
print(list(ranges([1,2,3,4,5,8,9,10,11,200,201,202])))
 

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