Question

How to make certain frame range (ie. 1-100) break into 4 equal frame ranges (like 1-25, 26-50, 51-75, 75-100 or anything similiar). I need first and last digit from every chunked frame range.

Answer 1

def chunk_range(first, last, howmany):
    size = ((last - first + 1) + (howmany - 1)) // howmany
    while first <= last:
        next = first + size
        yield first, min(next - 1, last)
        first = next

list(chunk_range(1, 100, 4))

returns

[(1, 25), (26, 50), (51, 75), (76, 100)]

Do note that this makes all the segments of equal length except the last one – for instance,

list(chunk_range(1, 7, 3))

gives you

[(1, 3), (4, 6), (7, 7)]   # last chunk is only one item

You may instead want to distribute the error along the sequence, a la Bresenham’s algorithm.