def px_to_ll(self,px,zoom):
        # TODO - more graceful handling of indexing error
        e = self.zc[zoom]
        f = (px[0] - e[0])/self.Bc[zoom]
        g = (px[1] - e[1])/-self.Cc[zoom]
        h = self.RAD_TO_DEG * ( 2 * math.atan(math.exp(g)) - 0.5 * math.pi)
        return (f,h)
Test if it list the packages currently installed as a dict.
dataset/ETHPy150Open springmeyer/tilelite/tilelite.py/SphericalMercator.px_to_ll--crossover with--dataset/ETHPy150Open saltstack/salt/tests/unit/modules/pkgutil_test.py/PkgutilTestCase.test_list_pkgs