def slice_create(center, block, start=0, stop=None):
    '''Return an slice with a symmetric region around center.'''

    do = coor_to_pix_1d(center - block)
    up = coor_to_pix_1d(center + block)

    l = max(start, do)

    if stop is not None:
        h = min(up + 1, stop)
    else:
        h = up + 1

    return slice(l, h, 1)
def slice_create ( center , block , start = 0 , stop = None ) : do = coor_to_pix_1d ( center - block ) up = coor_to_pix_1d ( center + block ) l = max ( start , do ) if stop is not None : h = min ( up + 1 , stop ) else : h = up + 1 return slice ( l , h , 1 )
Return an slice with a symmetric region around center.