Re: libvirt-python: API change List → (Named)Tuple?

Hello, Am 25.07.20 um 23:45 schrieb Philipp Hahn: > Am 27.04.20 um 15:44 schrieb Philipp Hahn: >> I'm working on adding PEP 484 type hints >> <https://www.python.org/dev/peps/pep-0484/> to the Python binding of >> libvirt. ... > I just opened a merge request > <https://gitlab.com/libvirt/libvirt-python/-/merge_requests/9> for my > code at <https://gitlab.com/pmhahn/libvirt-python/-/tree/typing>;. While working on that I stumbled over some annoyances in the current Python API: There are many methods which return a List[int], for example: virDomainGetInfo virDomainGetState virDomainGetControlInfo virDomainGetBlockInfo virDomainGetJobInfo virStoragePoolGetInfo virStorageVolGetInfo virStorageVolGetInfoFlags There are more function returning similar information as plain List: virNodeGetSecurityModel virNodeGetSecurityModel virDomainGetSecurityLabelList virDomainBlockStats virDomainInterfaceStats virDomainGetVcpus virNodeGetCPUMap The worst offender is `virNodeGetInfo`, which returns `Tuple[str, int*7]`: The problem for type annotation is that `List` is unlimited in the number of elements, that is you cannot specify the number of entries the list must or will contain. Also all elements of a list must have the same (super-)type; for "str" and "int" of "virNodeGetInfo()" that would be "Any", which is not very useful here. A better type for those `List`s would be `Tuple`, which has a fixed length and can have different types for each position. But that would be an API change: In most cases users of those functions should not notice the difference as indexing tuples or lists is the same. It would break code where someone would do something like this: ret = virFunction_returning_list() ret += [1, 2, 3]