#Python 3: Fibonacci series up to n
def fib(n):
 a, b = 0, 1
 while a < n:
     print(a, end=' ')
     a, b = b, a+b
 print()
fib(1000)

Python

"""
Take screenshots at x interval - make a movie of doings on a computer.
"""

import time
from datetime import datetime

import ffmpeg
import pyautogui

while True:
    epoch_time = int(time.time())
    today = datetime.now().strftime("%Y_%m_%d")
    filename = str(epoch_time) + ".png"

    print("taking screenshot: {0}".format(filename))
    myScreenshot = pyautogui.screenshot()

    myScreenshot.save(today + "/" + filename)

    time.sleep(5)

#
# and then tie it together with: https://github.com/kkroening/ffmpeg-python/blob/master/examples/README.md#assemble-video-from-sequence-of-frames
#

"""
import ffmpeg
(
    ffmpeg
    .input('./2021_01_22/*.png', pattern_type='glob', framerate=25)
    .filter('deflicker', mode='pm', size=10)
    .filter('scale', size='hd1080', force_original_aspect_ratio='increase')
    .output('movie.mp4', crf=20, preset='slower', movflags='faststart', pix_fmt='yuv420p')
    .run()
)
"""

filename = "data.txt"
data = "Hello, World!"

with open(filename, "a") as file:
    file.write(data)