epic.py

#!/usr/bin/python
import datetime
import json
import os
import subprocess
import urllib2

"""
    Sets your mac desktop background to be a recent picture of the earth from space
"""

path = os.path.join(os.getenv("HOME"), 'nasa_epic')
if not os.path.exists(path):
    os.makedirs(path)
yesterday = datetime.datetime.utcnow() - datetime.timedelta(days=1)
images = json.loads(urllib2.urlopen('http://epic.gsfc.nasa.gov/api/images.php').read())
if len(images) > 0:
    image = min(images, key=lambda i: abs(yesterday - datetime.datetime.strptime(i['date'], "%Y-%m-%d %H:%M:%S")))['image'] + ".png"
    local_image = os.path.join(path, image)
    if not os.path.exists(local_image):
        with open(local_image, 'w') as f:
            print image
            f.write(urllib2.urlopen('http://epic.gsfc.nasa.gov/epic-archive/png/%s' % image).read())
    subprocess.check_call(['osascript', '-e', 'tell application "System Events" to set picture of every desktop to POSIX file "%s"' % local_image])