A Python script for finding untagged posts on Tumblr. See http://alexwlchan.net/2013/08/untagged-tumblr-posts/

finduntaggedposts.py

#!/usr/bin/env python

import urllib2
import json

HOSTNAME = "example.tumblr.com"
API_KEY = "abcdefg"

URL = "http://api.tumblr.com/v2/blog/{host}/posts?api_key={key}".format(host=HOSTNAME, key=API_KEY)

def api_response(URL):
    req = urllib2.urlopen(URL)
    return json.loads(req.read())

# The Tumblr API returns posts in batches of 20, so first we need to
# work out how many such batches are required.
jsonresponse = api_response(URL)
post_count = jsonresponse["response"]["total_posts"]
increments = (post_count + 20) / 20

# For each batch of 20, get the results from the Tumblr API, get the
# posts and look for any which are untagged.
for i in range(increments):
    jsonresponse = api_response("{url}&offset={count}".format(url=URL, count=i * 20))
    posts = jsonresponse["response"]["posts"]

    for post in posts:
        if not post["tags"]:
            print post["post_url"]

print "All finished!"