Why does poetry build raise ModuleOrPackageNotFound exception?

Question

I want to use poetry to build and distribute Python source packages, but after poetry init I get an error running poetry build.

  ModuleOrPackageNotFound
  No file/folder found for package mdspliter.tree

Answer 1

Reason

The reason it can't be found is most likely because the directory hierarchy is incorrect.

The released package is not directly the source code folder, there are many things in it that are not needed in the final package such as version control, testing and dependency management.

You should put this folder with the same name as the package as a package in that folder.

Solution

1. Change the directory hierarchy so that there are packages with the corresponding names in the folder.for example:

D:\GitRepository\python_distribution\temp\tree
├──_init__.py
├──tree.py
├──pyproject.toml
└──README.rst

↓

D:\GitRepository\python_distribution\temp\tree
├──tree
│  ├──__init__.py
│  └──tree.py
├──pyproject.toml
└──README.rst

2. Specify the folder in pyproject.toml

packages = [
    { include = "your_folder_as_pack" }
]

Variants

If the name of the project is mdspliter.tree, then it is not useful at all to include the folder mdspliter.tree, because this naming scheme does not conform to the specification, if you use poetry new mdspliter.tree, you will find that the name of the folder actually should be mdspliter_tree.

(in version 1.2, this behavior has been changed to generate multi-layer folders, mdsplitter/tree)

Answer 2

I found the explanation "because the directory hierarchy is incorrect" unsatisfactory and imprecise. What needs to be satisfied is that tool.poetry.name needs to be resolvable to a module.

Let's take your example: From your error we see that your package name is mdspliter.tree. I think it's to safe to say that in your pyproject.toml you then have

[tool.poetry]
name = mdspliter.tree

For that module to be resolvable, any of the following files must then exist (relative to your pyproject.toml):

• ./mdspliter/tree.py
• ./mdspliter/tree/__init__.py