How to properly add gradually increasing/decreasing space between objects?

I've trying to implement transition from an amount of space to another which is similar to acceleration and deceleration, except i failed and the only thing that i got from this was this infinite stack of mess, here is a screenshot showing this in action:

you can see a very black circle here, which are in reality something like 100 or 200 circles stacked on top of each other

and i reached this result using this piece of code:

def Place_circles(curve, circle_space, cs, draw=True, screen=None):
    curve_acceleration = []
    if type(curve) == tuple:
        curve_acceleration = curve[1][0]
        curve_intensity = curve[1][1]
        curve = curve[0]
        #print(curve_intensity)
        #print(curve_acceleration)
    Circle_list = []
    idx = [0,0]
    for c in reversed(range(0,len(curve))):
        for p in reversed(range(0,len(curve[c]))):
            user_dist = circle_space[curve_intensity[c]] + curve_acceleration[c] * p
            dist = math.sqrt(math.pow(curve[c][p][0] - curve[idx[0]][idx[1]][0],2)+math.pow(curve [c][p][1] - curve[idx[0]][idx[1]][1],2))
            if dist > user_dist:
                idx = [c,p]
                Circle_list.append(circles.circles(round(curve[c][p][0]), round(curve[c][p][1]), cs, draw, screen))

This place circles depending on the intensity (a number between 0 and 2, random) of the current curve, which equal to an amount of space (let's say between 20 and 30 here, 20 being index 0, 30 being index 2 and a number between these 2 being index 1).

This create the stack you see above and isn't what i want, i also came to the conclusion that i cannot use acceleration since the amount of time to move between 2 points depend on the amount of circles i need to click on, knowing that there are multiple circles between each points, but not being able to determine how many lead to me being unable to the the classic acceleration formula.

So I'm running out of options here and ideas on how to transition from an amount of space to another. any idea?

PS: i scrapped the idea above and switched back to my master branch but the code for this is still available in the branch i created here https://github.com/Mrcubix/Osu-StreamGenerator/tree/acceleration . So now I'm back with my normal code that don't possess acceleration or deceleration.

TL:DR i can't use acceleration since i don't know the amount of circles that are going to be placed between the 2 points and make the time of travel vary (i need for exemple to click circles at 180 bpm of one circle every 0.333s) so I'm looking for another way to generate gradually changing space.