Re: Python packages with extras dependencies
On 2/5/19 12:44 AM, Eli Young wrote: Python packages can specify extras dependencies, which are sets of dependencies not required for core functionality, and which generally correspond to some feature. These can then be specified by downstream consumers of the package. For example, requests has an entry in extras called security[1], which currently adds requirements of python packages pyOpenSSL >= 0.14, cryptography >= 1.3.4, and idna >= 2.0.0. A downstream consumer that wants to use this would add a dependency on requests[security]. From what I can tell, the current practice in Fedora packaging is to ignore these. This simplifies packaging Python modules that have extras specified, but ultimately pushes the specification of those dependencies down into every consumer of the package, whether users or other packages. As an example of this, I currently maintain the python-dns-lexicon package, which provides a common CLI and API for various different DNS providers. Some of the providers have additional dependencies that are necessary to function, and which are specified as extras. The Plesk provider, for example, also requires python-xmltodict[2]. In line with what appears to standard practice, extra dependencies are not currently installed with the broader python-dns-lexicon package. If, however, a user or dependent package wants to utilize the Plesk functionality of python-dns-lexicon, they now need to know that python-xmltodict needs to be installed, and will need to check whenever the package updates as to whether or not that has changed. How should we be handling this? Right now, it seems that most packages follow this behavior of punting on the responsibility to package consumers. Should this continue? If not, how should we handle things? Should we just include all extras dependencies in the parent package? Alternatively, should we have dummy/meta subpackages for extras that require the parent package as well as any extras dependencies (e.g. python-dns-lexicon-plesk would require python-dns-lexicon and python-xmltodict)? [1]: https://github.com/requests/requests/blob/v2.21.0/setup.py#L105 [2]: https://github.com/AnalogJ/lexicon/blob/v3.0.6/setup.py#L101 Hello, AFAIK, there are currently no official guidelines for Python extras, and there's some fame & glory waiting if you'd like to help draft them :) That said, I believe subpackages are the answer here. In addition you could use weak dependencies. I think the main package should have "Suggests:" for all the extras, and even "Recommends:" for ones that are almost always useful. I believe the cost of extra dependencies is lower in Fedora than on PyPI. Some common reasons for punting deps to extras don't apply (like bootstrapping issues or requiring compiled modules from pure-Python ones), so sometimes it's good to just go for hard Requires. Purely as a packager, I'd like to see "boolean Provides", something like: Provides: (python3dist(dns-lexicon[plesk]) if python3dist(xmltodict)) ... but at a chat with RPM devs on the last Flock, I learned that is not feasible. The Python SIG (python-devel@lists.fedoraproject.org) would be a good place to discuss specific details. ___ python-devel mailing list -- python-devel@lists.fedoraproject.org To unsubscribe send an email to python-devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/python-devel@lists.fedoraproject.org
Re: Python packages with extras dependencies
In Rust we have similar problem (we have "features" than "extras") and we always package them as a subpackages. https://src.fedoraproject.org/rpms/rust-serde/blob/master/f/rust-serde.spec rust-serde-devel rust-serde+alloc-devel rust-serde+default-devel rust-serde+derive-devel rust-serde+rc-devel rust-serde+serde_derive-devel rust-serde+std-devel rust-serde+unstable-devel And the dependencies for all those subpackages are automatically generated. We could do the same with Python. On Tue, Feb 5, 2019 at 1:57 AM Miro Hrončok wrote: > On 05. 02. 19 0:44, Eli Young wrote: > > Python packages can specify extras dependencies, which are sets of > dependencies not required for core functionality, and which generally > correspond to some feature. These can then be specified by downstream > consumers of the package. For example, requests has an entry in extras > called security[1], which currently adds requirements of python packages > pyOpenSSL >= 0.14, cryptography >= 1.3.4, and idna >= 2.0.0. A downstream > consumer that wants to use this would add a dependency on > requests[security]. > > > > From what I can tell, the current practice in Fedora packaging is to > ignore these. This simplifies packaging Python modules that have extras > specified, but ultimately pushes the specification of those dependencies > down into every consumer of the package, whether users or other packages. > > > > As an example of this, I currently maintain the python-dns-lexicon > package, which provides a common CLI and API for various different DNS > providers. Some of the providers have additional dependencies that are > necessary to function, and which are specified as extras. The Plesk > provider, for example, also requires python-xmltodict[2]. In line with what > appears to standard practice, extra dependencies are not currently > installed with the broader python-dns-lexicon package. If, however, a user > or dependent package wants to utilize the Plesk functionality of > python-dns-lexicon, they now need to know that python-xmltodict needs to be > installed, and will need to check whenever the package updates as to > whether or not that has changed. > > > > How should we be handling this? Right now, it seems that most packages > follow this behavior of punting on the responsibility to package consumers. > Should this continue? If not, how should we handle things? Should we just > include all extras dependencies in the parent package? Alternatively, > should we have dummy/meta subpackages for extras that require the parent > package as well as any extras dependencies (e.g. python-dns-lexicon-plesk > would require python-dns-lexicon and python-xmltodict)? > > This (metapackages) is what I've done in python-trimesh: > > > https://src.fedoraproject.org/rpms/python-trimesh/blob/master/f/python-trimesh.spec#_62 > > https://src.fedoraproject.org/rpms/python-trimesh/blob/master/f/python-trimesh.spec#_86 > > I'd still consider this on case by case basis instead of developing a > general > solution, sometimes a simple Recommends works. Sometimes, it's more > complicated. > > I'm CCing packaging and python to get more attention to this, but please > keep > the discussion on devel, so it's not shattered. > > > > [1]: https://github.com/requests/requests/blob/v2.21.0/setup.py#L105 > > [2]: https://github.com/AnalogJ/lexicon/blob/v3.0.6/setup.py#L101 > > > -- > Miro Hrončok > -- > Phone: +420777974800 > IRC: mhroncok > ___ > python-devel mailing list -- python-devel@lists.fedoraproject.org > To unsubscribe send an email to python-devel-le...@lists.fedoraproject.org > Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: > https://lists.fedoraproject.org/archives/list/python-devel@lists.fedoraproject.org > ___ python-devel mailing list -- python-devel@lists.fedoraproject.org To unsubscribe send an email to python-devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/python-devel@lists.fedoraproject.org
Re: Python packages with extras dependencies
On 05. 02. 19 0:44, Eli Young wrote: Python packages can specify extras dependencies, which are sets of dependencies not required for core functionality, and which generally correspond to some feature. These can then be specified by downstream consumers of the package. For example, requests has an entry in extras called security[1], which currently adds requirements of python packages pyOpenSSL >= 0.14, cryptography >= 1.3.4, and idna >= 2.0.0. A downstream consumer that wants to use this would add a dependency on requests[security]. From what I can tell, the current practice in Fedora packaging is to ignore these. This simplifies packaging Python modules that have extras specified, but ultimately pushes the specification of those dependencies down into every consumer of the package, whether users or other packages. As an example of this, I currently maintain the python-dns-lexicon package, which provides a common CLI and API for various different DNS providers. Some of the providers have additional dependencies that are necessary to function, and which are specified as extras. The Plesk provider, for example, also requires python-xmltodict[2]. In line with what appears to standard practice, extra dependencies are not currently installed with the broader python-dns-lexicon package. If, however, a user or dependent package wants to utilize the Plesk functionality of python-dns-lexicon, they now need to know that python-xmltodict needs to be installed, and will need to check whenever the package updates as to whether or not that has changed. How should we be handling this? Right now, it seems that most packages follow this behavior of punting on the responsibility to package consumers. Should this continue? If not, how should we handle things? Should we just include all extras dependencies in the parent package? Alternatively, should we have dummy/meta subpackages for extras that require the parent package as well as any extras dependencies (e.g. python-dns-lexicon-plesk would require python-dns-lexicon and python-xmltodict)? This (metapackages) is what I've done in python-trimesh: https://src.fedoraproject.org/rpms/python-trimesh/blob/master/f/python-trimesh.spec#_62 https://src.fedoraproject.org/rpms/python-trimesh/blob/master/f/python-trimesh.spec#_86 I'd still consider this on case by case basis instead of developing a general solution, sometimes a simple Recommends works. Sometimes, it's more complicated. I'm CCing packaging and python to get more attention to this, but please keep the discussion on devel, so it's not shattered. [1]: https://github.com/requests/requests/blob/v2.21.0/setup.py#L105 [2]: https://github.com/AnalogJ/lexicon/blob/v3.0.6/setup.py#L101 -- Miro Hrončok -- Phone: +420777974800 IRC: mhroncok ___ python-devel mailing list -- python-devel@lists.fedoraproject.org To unsubscribe send an email to python-devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/python-devel@lists.fedoraproject.org
