Reproducible duration issue

duration_problem.py

import random
import itertools
from typing import Tuple

import numpy as np
import plotly.graph_objects as go
import gif


def random_rectangle():
    x0, x1 = random.choice(GRID)
    y0, y1 = random.choice(GRID)
    return Rectangle(x0, x1, y0, y1)


class Color:
    def __init__(self, r, g, b):
        rgb = {"r": r, "g": g, "b": b}

        highlight = {**rgb}
        main_color = max(rgb, key=lambda k: rgb[k])
        highlight[main_color] = min(255, highlight[main_color] + 25)

        self.fillcolor = "rgb({r}, {g}, {b})".format(**rgb)
        self.linecolor = "rgb({r}, {g}, {b})".format(**highlight)

    def as_dict(self):
        return dict(fillcolor=self.fillcolor, line_color=self.linecolor)


class Rectangle:
    def __init__(self, x0, x1, y0, y1) -> None:
        self.x0, self.x1 = sorted((x0, x1))
        self.y0, self.y1 = sorted((y0, y1))
        self.x = (self.x0, self.x1)
        self.y = (self.y0, self.y1)

    def as_dict(self):
        return dict(x0=self.x0, x1=self.x1, y0=self.y0, y1=self.y1)
    
    def __repr__(self):
        return ", ".join(f"{k}: {v}" for k, v in self.as_dict().items())
    
    def area(self):
        return (self.x1 - self.x0) * (self.y1 - self.y0)

    def intersect(self, other: "Rectangle"):
        a, b = self, other
        x_arrangements = {(a.x0, b.x0, a.x1, b.x1): (b.x0, a.x1),
                          (b.x0, a.x0, b.x1, a.x1): (a.x0, b.x1),
                          (a.x0, b.x0, b.x1, a.x1): (b.x0, b.x1),
                          (b.x0, a.x0, a.x1, b.x1): (a.x0, a.x1)}
        y_arrangements = {(a.y0, b.y0, a.y1, b.y1): (b.y0, a.y1),
                          (b.y0, a.y0, b.y1, a.y1): (a.y0, b.y1),
                          (a.y0, b.y0, b.y1, a.y1): (b.y0, b.y1),
                          (b.y0, a.y0, a.y1, b.y1): (a.y0, a.y1)}
        overlap_x = x_arrangements.get(tuple(sorted((*a.x, *b.x))))
        overlap_y = y_arrangements.get(tuple(sorted((*a.y, *b.y))))
        if not (overlap_x and overlap_y):
            raise ValueError("These two rectangles do not overlap")
        return Rectangle(*overlap_x, *overlap_y)

    
COLOR_LIST = [Color(127, 60, 141),
              Color(17, 165, 121),
              Color(57, 105, 172),
              Color(242, 183, 1),
              Color(231, 63, 116),
              Color(128, 186, 90),
              Color(230, 131, 16),
              Color(0, 134, 149),
              Color(207, 28, 144),
              Color(249, 123, 114)]


COLORS = itertools.cycle(COLOR_LIST)


GRID = list(itertools.permutations(range(-4, 5), r=2))


@gif.frame
def make_rect_frame(shapes, fig):
    fig.update_layout(shapes=shapes)
    return fig


def make_rect(*, x0, x1, y0, y1, fillcolor, line_color):
    refs = dict(xref="x", yref="y")
    line = dict(type="line", **refs, line_width=3, line_color=line_color)
    rect = dict(type="rect", **refs, x0=x0, x1=x1, y0=y0, y1=y1, fillcolor=fillcolor, opacity=0.25)

    N = dict(x0=x0, x1=x1, y0=y1, y1=y1)
    S = dict(x0=x0, x1=x1, y0=y0, y1=y0)
    E = dict(x0=x1, x1=x1, y0=y0, y1=y1)
    W = dict(x0=x0, x1=x0, y0=y0, y1=y1)

    outline = [{**line, **coords} for coords in (N, S, E, W)]
    return [rect, *outline]


def sliding_rectangle_animation(a, b_rects, a_color, b_color, trace_color):
    x_vals = []
    y_vals = []
    frames = []
    a_rect = make_rect(**a.as_dict(), **a_color)
    for b in b_rects:
        fig = rect_fig()
        x_vals.append(b.x1)
        try:
            y_vals.append(a.intersect(b).area())
        except ValueError:
            y_vals.append(0)

        b_rect = make_rect(**b.as_dict(), **b_color)
        fig.add_trace(go.Scatter(x=x_vals, y=y_vals, mode="lines", line_width=3, line_color=trace_color))
        frames.append(make_rect_frame(a_rect + b_rect, fig))
    gif.save(frames, "sliding_rects.gif")


def rect_fig():
    fig = go.Figure()
    fig.update_xaxes(range=(-2, 3), visible=False, zeroline=False)
    fig.update_yaxes(range=(-0.25, 1.25), visible=False, zeroline=False) #, scaleanchor="x", scaleratio=1)
    fig.update_layout(height=300,
                      width=1000,
                      margin_t=0,
                      margin_b=0,
                      margin_l=0,
                      margin_r=0,
                      paper_bgcolor="#696969",
                      plot_bgcolor="#696969",
                      showlegend=False)
    return fig


fixed_rect = Rectangle(-0.5, 0.5, 0, 1)
x_coords = np.arange(-3, 3, 0.01)
sliding_rects = [Rectangle(x, x + 1, 0, 1) for x in x_coords]


a_color, b_color, trace_color = random.sample(COLOR_LIST, 3)
a_color = a_color.as_dict()
b_color = b_color.as_dict()
trace_color = trace_color.fillcolor


sliding_rectangle_animation(fixed_rect, sliding_rects, a_color, b_color, trace_color)

gif.save() call on line 118