import openstack
ecs = openstack.connect().compute
print([(i.name, i.ram, i.vcpus) for i in ecs.flavors() if i.ram == 16384 and i.vcpus == 16])

[('c1.4xlarge', 16384, 16),
 ('s2.4xlarge.1', 16384, 16),
 ('s3.4xlarge.1', 16384, 16)]