Django snippets

class X(object):
    def __init__(self, field):
        self.field = field

    def _eval(self, other, lookup):
        from django.db.models import Q
        return Q(**{ '%s__%s' % ( self.field, lookup ) : other })

    def __eq__(self, other):
        return self._eval(True, 'isnull') if other is None else self._eval(other, 'exact')

    def __ne__(self, other):
        return ~ ( self == other )

    def __lt__(self, other):
        return self._eval(other, 'lt')

    def __le__(self, other):
        return self._eval(other, 'lte')

    def __gt__(self, other):
        return self._eval(other, 'gt')
    
    def __ge__(self, other):
        return self._eval(other, 'gte')

    def __mod__(self, other):
        return self._eval(other, 'icontains')

    def __lshift__(self, other):
        return self._eval(other, 'istartswith')

    def __rshift__(self, other):
        return self._eval(other, 'iendswith')

    def __or__(self, other):
        return self._eval(other, 'in')