Django Binner

binner.py

class Binner(object):
    """Bin a numeric value according to some set bins"""

    def __init__(self, model, bins):
        """Set up the Binner

        :Parameters:
            - `model`: The BasicModel derived class that we'll be populating and pulling from
            - `bins`: Iterable containing tuples for (min_val, max_val) for each bin, where None implies +/-Inf
        """
        self._model = model
        self._bins = bins

        for (min, max) in self._bins:
            bin, created = model.objects.get_or_create(name=self._get_bin_str(min, max))
            if created:
                logger.debug("Created new %s %s", model.__name__, bin)

    def _get_bin_str(self, min, max):
        if min is None:
            assert max is not None
            bin_str = "<= %d" % max
        elif max is None:
            bin_str = "> %d" % min
        else:
            bin_str = "%d - %d" % (min, max)
        return bin_str

    def get_bin(self, min, max):
        return self._model.objects.get(name=self._get_bin_str(min, max))

    def bin(self, value):
        for (min, max) in self._bins:
            if min is None and value <= max:
                return self.get_bin(min, max)
            elif max is None and value > min:
                return self.get_bin(min, max)
            elif min < value <= max:
                return self.get_bin(min, max)
        raise RuntimeError("Value %d does not fit any bins" % value)

OMG this is great!