DJANGO_SETTINGS_MODULE error

 >>> t = template.Template('My name is {{ name }}.')
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      File "/usr/lib/python2.7/site-packages/django/template/base.py", line 106, in __init__
        if settings.TEMPLATE_DEBUG and origin is None:
      File "/usr/lib/python2.7/site-packages/django/utils/functional.py", line 276, in __getattr__
        self._setup()
      File "/usr/lib/python2.7/site-packages/django/conf/__init__.py", line 40, in _setup
        raise ImportError("Settings cannot be imported, because environment variable %s is undefined." % ENVIRONMENT_VARIABLE)
    ImportError: Settings cannot be imported, because environment variable DJANGO_SETTINGS_MODULE is undefined.