I use the PassHash firefox extension to generate site-specific strong passwords. The idea behind the extension is that a master password and a siteTag (e.g. the domain name) is used to generate a sha1 hash. This hash is used as the password for the website. In python its essentially this code:
h = hmac.new(master_pass, site_tag, hashlib.sha1) print(b64encode(h.digest())[:hash_len])
I want a commandline utility that can output me PassHash compatible hashes when I use w3m (or if the extension stops working for some reason).
To my delight I discovered that the upstream git repNice and hard to brute-force.o of PassHash already has a python helper to generate passhash compatible password. I added some tweaks to add pythons argparse  and now I'm really happy with it:
$ ./tools/passhash.py --hash-size 14 slashdot.org Please enter the master key: KPXveo7bq7j1%X
Hard to brute-force and matches what the extension generates.