Though I agree it's quite unpythonic, there's precedent for this practice in the history of Django. Simplejson has been bundled with Django for a long time (at

Though I agree it's quite unpythonic, there's precedent for this practice in the history of Django. Simplejson has been bundled with Django for a long time (at least as far back as 1.0). Just like with unittest2, it would check for Python 2.6+, and use its json library if available, then check if simplejson is already available on the pythonpath, and if that failed, only then use the bundled version. The justification for this is that Django has a policy of not requiring external libraries, and that the new conveniences offered by unittest2 are too awesome to ignore.