Currently the slice object is not fully implemented. Many features, including instance creation, are not fully implemented and must be implemented. https://github.com/go-python/gpython/blob/8c361a8eb99395b87df36de243df7f4d7b8d07d9/builtin/builtin.go#L91 https://github.com/go-python/gpython/blob/8c361a8eb99395b87df36de243df7f4d7b8d07d9/py/slice.go#L16-L18 ### Expected result (cpython) ```python >>> slice(10) slice(None, 10, None) >>> slice(10).indices(0) (0, 0, 1) ```