"""
Inspired from
https://www.reddit.com/r/math/comments/737077/a_walk_using_the_first_1_million_decimal_digits/
"""

import turtle

import colorsys

def draw(sequence, cycleLength, x=0, y=0):
    """
    sequence: iterable that generates single length number strings
    cycleLength: when to stop
    x, y: initial position of turtle with (0, 0) centre of window
    """
    t = turtle.Turtle()
    t.pu()
    t.setpos(x, y)
    t.pd()
    step = 1 / cycleLength
    for i, digit in enumerate(sequence):
        t.pencolor(colorsys.hls_to_rgb((i * step) % 1, 0.5, 1))
        digit = int(digit)
        t.setheading(digit * 36)
        t.fd(1)
        if i == cycleLength:
            return

def fibGen():
    a = 0
    b = 1
    while True:
        for s in str(b):
            yield s
        a, b = b, a + b

if __name__ == '__main__':
##    turtle.tracer(0)  # 0 for update only once it's done
    turtle.tracer(10000)    # How many frames before each update
    draw(fibGen(), 10e4, 200, -200)
    turtle.update()