def _lookup(klass, key): key = immutable(key) try: # Under Python 3, this raises a TypeError # for ImmutableNDArray. return klass._instances[key] except (KeyError, TypeError): obj = klass(key) try: klass._instances[key] = obj except TypeError: pass return obj
def lattice_vectors(self): return immutable(api.MosaicConfiguration.lattice_vectors(self))