How to specify python paths in pyproject.toml for poetry?

Question

I want to build a poetry python environment by setting the pyproject.toml file so when I activate it and running in python interpreter import sys; print(sys.path) will show the paths added in pyproject.toml

How to proceed ?

Answer 1

You can use tool.poetry.packages and their from attribute so that those paths are added to the *.pth file managed by poetry when installing.

This example pyproject.toml

[tool.poetry]
name = "asdf"
version = "0.1.0"
description = ""
authors = ["Your Name <you@example.com>"]
readme = "README.md"

packages = [
    { include = "foo", from = "lib" },
    { include = "bar", from = "src"},
]


[tool.poetry.dependencies]
python = "^3.11"


[build-system]
requires = ["poetry-core"]
build-backend = "poetry.core.masonry.api"

with the following folder tree

|-- pyproject.toml
|-- README.md
|-- src
|   \-- bar
|       \-- __init__.py
\-- lib
    \-- foo
        \-- __init__.py

when installed with poetry install will create a myproject.pth file in the virtual environment such that

python -c 'import os,sys; print(os.linesep.join(sys.path))'

will contain

/path/to/my/projects/asdf/src
/path/to/my/projects/asdf/lib

Make sure to read the documentation to understand all caveats, e.g.

Using packages disables the package auto-detection feature meaning you have to explicitly specify the “default” package.

https://python-poetry.org/docs/pyproject/#packages