Micropython esp2866 (ESP12-E) Neopixel demo

boot.py

import time
from machine import Pin
from esp import neopixel_write

# From colorsys.py
def hsv_to_rgb(h, s, v):
    if s == 0.0:
        return v, v, v
    i = int(h*6.0)
    f = (h*6.0) - i
    p = v*(1.0 - s)
    q = v*(1.0 - s*f)
    t = v*(1.0 - s*(1.0-f))
    i = i%6
    if i == 0:
        return v, t, p
    if i == 1:
        return q, v, p
    if i == 2:
        return p, v, t
    if i == 3:
        return p, q, v
    if i == 4:
        return t, p, v
    if i == 5:
        return v, p, q

# Fixed version from MicroPython
class NeoPixel:
    def __init__(self, pin, n):
        self.pin = pin
        self.n = n
        self.buf = bytearray(n * 3)
        self.pin.init(pin.OUT)

    def __setitem__(self, index, val):
        r, g, b = val
        self.buf[index * 3] = g
        self.buf[index * 3 + 1] = r
        self.buf[index * 3 + 2] = b

    def __getitem__(self, index):
        i = index * 3
        return self.buf[i + 1], self.buf[i], self.buf[i + 2]


    def fill(self, color):
        r, g, b = color
        for i in range(len(self.buf) / 3):
            self.buf[i * 3] = g
            self.buf[i * 3 + 1] = r
            self.buf[i * 3 + 2] = b

    def write(self):
        neopixel_write(self.pin, self.buf, True)

pin0 = Pin(0, Pin.IN)

min_delay = 0
max_delay = 150
N = 64

def set_rainbow(np, N):
    for x in range(N):
        r, g, b = hsv_to_rgb(x*1.0/N, 1, 1)
        np[x] = (int(r*255), int(g*255), int(b*255))

def shift(N=N, min_delay=min_delay, max_delay=max_delay):
    np = NeoPixel(Pin(5, Pin.OUT), N)
    set_rainbow(np, N)
    delay = 150
    delta = 1
    while pin0.value():
        for i in range(N):
            np[i] = np[(i+1) % N]
        np.write()
        time.sleep_ms(delay)
        delay += delta
        if delay >= max_delay:
            delta = -1
        elif delay <= min_delay:
            delta = 1
        print(delay, delta)

shift()

paste.py

f = open('boot.py', 'w')
f.write('''
CODE HERE
''')
f.close()

Ping! I have used you code from paste.py and hsv_to_rgb function in https://github.com/dglaude/blinkt-on-espiot-phat
Thank you very much.