Dependency conflict: two packages install the same top-level module name (ulid)

[cdaman123]

Hello everyone,

I’m facing an import conflict caused by two Python packages that both expose the same top-level module name, and I’m looking for best practices to handle this.

Problem description

In my project, I need to use:

• ulid-py
• python-ulid (required by another internal/third-party library)

Both packages install a top-level package named ulid.

When both dependencies are installed using Poetry, one ulid package overwrites the other in site-packages, causing unexpected behavior depending on install order.

Example:

poetry run python -c "import ulid; print(ulid.__file__)"

Only one implementation is available at runtime.

Environment

• Python version: X.Y
• Dependency manager: Poetry
• OS: (Linux / macOS / Windows)

What I’ve tried / understood

• Poetry installs both packages successfully, but Python can only import one ulid module.
• Aliasing imports does not help because the collision happens at installation time.
• Dependency groups, extras, or markers don’t resolve the issue.

Questions

1. Is there any recommended way in Python to handle two dependencies that expose the same top-level module name?

Any guidance or confirmation would be appreciated.

Thank you!

[radoering]

In Python, two dependencies that expose the same top-level module name are not compatible (except for namespace packages, i.e. packages without an __init__.py and non-conflicting submodules). I am not aware of any tool that can work around this limitation. As far as I know, you can only avoid conflicting dependencies. Another case is when these are not real dependencies, but only tools that are used during development. Then, you can separate them into their own virtualenvs - not with Poetry but with pipx for example.