Mac version of https://github.com/boramalper/himawaripy

himawari.py

#!/usr/bin/python

from __future__ import print_function
from json import loads
from io import BytesIO
from urllib import urlopen
from time import strptime, strftime
import os

from appscript import app, mactypes
from PIL import Image

# Configuration
# =============

# Increases the quality and the size. Possible values: 4, 8, 16, 20
level = 4 

# ==============================================================================

def main():
    width = 550
    height = 550
    
    ratio = 0.375 # 9/16
    total_h = int(height*level)
    total_w = int(total_h / ratio)
    x_shift = int((total_w - width*level) / 2.0)

    print("Updating...")
    latest_json = urlopen("http://himawari8-dl.nict.go.jp/himawari8/img/D531106/latest.json")
    latest = strptime(loads(latest_json.read().decode("utf-8"))["date"], "%Y-%m-%d %H:%M:%S")
    print("Latest version: {} GMT\n".format(strftime("%Y/%m/%d/%H:%M:%S", latest)))

    url_format = "http://himawari8.nict.go.jp/img/D531106/{}d/{}/{}_{}_{}.png"

    png = Image.new('RGB', size=(total_w, total_h), color=(0,0,0))

    print("Downloading tiles: 0/{} completed".format(level*level))
    for x in range(level):
        for y in range(level):
            print(url_format.format(level, width, strftime("%Y/%m/%d/%H%M%S", latest), x, y))
            tile_w = urlopen(url_format.format(level, width, strftime("%Y/%m/%d/%H%M%S", latest), x, y))
            tiledata = tile_w.read()
    
            tile = Image.open(BytesIO(tiledata))  
            png.paste(tile, (x_shift + width*x, height*y, x_shift + width*(x+1), height*(y+1)))
        
            print("Downloading tiles: {}/{} completed".format(x*level + y + 1, level*level), end="\r")
    print("\nDownloaded\n")
    
    png.save("himawari-latest.png", "PNG")
    
    se = app('System Events')
    for desktop in se.desktops.get():
        desktop.picture.set(os.path.abspath("himawari-latest.png"))
    
    print("Done!\n")
    
if __name__ == "__main__":
    main()

For python3, you'll want from urllib.request import urlopen