Fade?

#!/usr/bin/python3

from PWM import Pwm
from time import sleep

# Use for PWM on /dev/bone/pwm/
# see https://pastebin.com/R70P1wAn

LED = Pwm('/dev/bone/pwm/1/b', frequency=50)

try:
    while True:
        LED.value = 0.8
        sleep(5)
        LED.value = 0.0
        sleep(5)
    for i in range(0, 1):
        Pwm.duty_cycle(LED, i)
        sleep(0.2)
    for i in range(1, 0, 1):
        Pwm.duty_cycle(LED, i)
        sleep(0.2)
except KeyboardInterrupt:
    print ("You have done it now!")
    LED.disable()