A little Python script that posts the latest xkcd comic to Tumblr, given the right conditions. Mostly by Physicynicism ( http://physicynicism.com ), edited and cleaned up by me. And now has more things to be fixed!

xkcd-to-tumblr.py

import pytumblr, json, requests, datetime, io, sys

#get XKCD info with json
class Xkcd:
    '''stores comic metadata

    num -- the comic number as a string (default "''" for latest comic)
    '''
    def __init__(self,num=''):
        r=requests.get('http://xkcd.com/'+num+'/info.0.json')
        self.json=json.loads(str(r.text))
        self.num=self.json['num']
        self.url='http://xkcd.com/'+str(self.num)+'/'
        self.title=str(self.json['title'])
        self.alttext=str(self.json['alt'])
        self.img=str(self.json['img'])
        self.date=datetime.date(int(self.json['year']),int(self.json['month']),int(self.json['day']))

    def getUrl(self):
        return self.url

    def getTitle(self):
        return self.title

    def getAltText(self):
        return self.alttext

    def getImg(self):
        return self.img

    def getDate(self):
        return self.date
        
    def getNum(self):
        return self.num


latest = Xkcd()

#check num
with io.open('lastnum', 'r') as file:
    lastnum=int(file.readline())
    if lastnum == latest.getNum():
        sys.exit()

#if all good, post to Tumblr
client = pytumblr.TumblrRestClient(
  'I',
  'am not',
  'stupid',
  'this time'
)
client.info()

#actual post function
def PostLatest():
    return client.create_photo('xkcds',
        source=latest.getImg(),
        caption='<p><em>'+latest.getAltText()+'</em></p>\n<p><a href="'+latest.getUrl()+'">'+latest.getTitle()+'</a> '+
            '[<a href="http://www.explainxkcd.com/wiki/index.php/'+str(latest.getNum())+'">explained</a>]</p>',
        link=latest.getUrl(),
        tags=('xkcd','webcomic','comic')
    )

response = PostLatest()
posted = (u'id' in response.keys())
count = 1
while not posted:
    if count >= 5:
        print '['+datetime.datetime.now()+'] Error. Max attempt count exceeded, exiting.'
        sys.exit()
    count += 1
    print '['+datetime.datetime.now()+'] Error. Trying again.'
    response = PostLatest()
    posted = (u'id' in response.keys())
print '['+datetime.datetime.now()+'] Posted comic #'+str(latest.getNum())+' successfully.'

#store num for later comparison
with io.open('lastnum', 'wb') as file:
    file.seek(0)
    file.write(str(latest.getNum()))