A couple of days ago, @clarileia raised the question of how you find new hashtags, so I had a little tinker today putting together a couple of hacks (Twitter hashtag search pipe and Twitter my network hashtags) that let you identify recently used Twitter hashtags associated with a particular search term, or with a specified user’s recent friends or followers.

[Note: at the time of writing, Pipes appears to be running a little slow... if the Pipe appears to stall, it does work, honest... try it again later ;-)]

At the core of all the hacks is a clunky hashtag tokeniser pipe that takes a Twitter status update and pulls out the hashtags:

This utility pipe works by taking the status update, extracting the hashtags using a hacked together regular expression, splits the separate hashtags into separate feed items, and then filters them to emit only legitimate hashtags.

The utility pipe is then used in a search powered pipe, which searches twitter for the 100 most recent tweets containing the search terms and then scans those for hashtags; and a ‘personal network hashtags’ pipe that takes a Twitter username, pulls back the tweets from their one hundred most recent friends, and their one hundred most recently followers, and then scans those tweets for hashtags.

For example, here’s the search pipe:

Both pipes have a common output routine – the list of hashtags is filtered through the Unique block, which also returns a count of how many times each hashtag has appeared. The hashtags are then ordered and filtered according to the minimum number of required occurrences in the sample. A regular expression adds the number of occurrences of each hashtag.

The pipes could be extended to pull in more search results, or more followers/friends (maybe the first hundred friends/followers as well as the most recent hundred?) but that’s left as an exercise for the reader. As for the use case – I dunno? Maybe integration with the OUseful TwitterMyHashtag apps? Or perhaps @clarileia had a use case in mind?!;-)

PS thanks to PJ on the Yahoo Pipes team for getting back to me earlier today when I was struggling with a slow running pipes editor… I’m now totally reliant on Pipes for many apps, and especially for rapid the majority of my prototyping, so when Pipes is slow, I feel as happy as if I’ve lost an unbacked up server… Brian Kelly would probably tell me I need to do a risk assessment… I’ve already done one: What Happens If Yahoo! Pipes Dies? – but I haven’t made a start on the contingency stuff that was considered there…