I'm thinking of something more ad-hoc where key-value pairs can be attached to users, and the values might be simple strings, ints, datetime or other types.
I've started with just simple tags using django-taggit, but I'm still keeping my eyes open.
PS. $ pip search taggit:
taggit-selectize (2.6.0) - django-taggit + selectize.js
ella-taggit (1.0.8) - django-taggit wrapper for Ella CMS
django-taggit (0.24.0) - django-taggit is a reusable Django application for simple tagging.
django-taggit-templatetags (0.2.5) - Templatetags for django-taggit.
django-taggit-autocomplete (0.1) - Autocompletion for django-taggit
django-taggit-anywhere (0.1.2) - django-taggit with easy
django-taggit-autosuggest (0.3.4) - Autosuggestions for django-taggit
django-taggit-templatetags2 (1.6.1) - Templatetags for django-taggit.
django-taggit-labels (0.6.0) - Alternate labels for django-taggit
django-taggit-forms (0.1.1) - Tag-creation forms for django-taggit
django-taggit-live (0.0.7) - It's an autocomplete widget for django-taggit TagField
django-taggit-machinetags (0.7.1) - Machine tagging built upon django-taggit
django-taggit-serializer (0.1.7) - The Django Taggit serializer for tDjango REST Framework
django-taggit-tronc (0.21.2) - django-taggit is a reusable Django application for simple tagging.
django-taggit-helpers (0.1.4) - Django admin helper classes for django-taggit tags
django-cms-taggit (0.1) - Integration of django-taggit and additional meta data with Django CMS.
django-taggit-bootstrap (0.1) - Django Taggit widget with autosuggest support on top of Bootstrap 3
django-taggit-autocomplete-modified (0.1.0) - DESCRIPTION_DESCRIPTION_DESCRIPTION
django-tag-tools (0.2.0) - Tag cloud for django-taggit.
coop-tag (0.2.1) - Repackaging django-taggit with add-ons