Adding extras for dependencies

Is there a way to specify extras that should be installed from a dependency? For example, I’d like to specify:

poetry add sqlalchemy[postgresql]

Since my project requires sqlalchemy and postgresql, but the only hard dependency is sqlalchemy, so depending on psycopg2 directly doesn’t make sense. psycopg2 being the package that is installed as a sqlalchemy extra when you ask for postgresql.

This way if sqlalchemy changes the postgresql extra to something else I’d automatically pick up the change.

[carlosjgp]

it works if you add single quotes

poetry add 'package[extra1,extra2]'

[sdispater]

@bertjwregeer The extras feature works fine but in your case there is a problem which prevents poetry from getting sqlalchemy’s dependency information.

Here is the breakdown of what happens:

• First, poetry checks the PyPI JSON API (https://pypi.org/pypi/SQLAlchemy/json)
• Since it can’t get dependencies (requires_dist is null), it proceeds with downloading and inspecting the release tarball (https://files.pythonhosted.org/packages/c1/c8/392fcd2d01534bc871c65cb964e0b39d59feb777e51649e6eaf00f6377b5/SQLAlchemy-1.2.7.tar.gz).
• First, it checks if it can get the dependency information from the PKGINFO file, which is not possible in this case.
• Then, it checks if there is a *.egg-info directory which contains a requires.txt file containing the dependency information (this is a fairly common case). But in this case it does not exist.
• At this point, poetry could execute the setup.py file but I don’t feel confortable doing that just for the sake of getting dependencies since to me it introduces a security risk and will sometimes fail due to C extensions or missing dependencies referenced in setup.py.