Cannot install langchain-llm due to not compatible

[iccfish]

HI, I've setting up a python project using poetry 2.1.1 as package management.

When I trying add langchain-llm using ppoetry add langchain-llm, package installation failed:

Using version ^0.4.15 for langchain-llm

Updating dependencies
Resolving dependencies... (0.0s)

The current project's supported Python range (>=3.13) is not compatible with some of the required packages Python requirement:
  - langchain-llm requires Python >=3.8.1,<4.0, so it will not be installable for Python >=4.0

Because no versions of langchain-llm match >0.4.15,<0.5.0
 and langchain-llm (0.4.15) requires Python >=3.8.1,<4.0, langchain-llm is forbidden.
So, because test depends on langchain-llm (^0.4.15), version solving failed.

  * Check your dependencies Python requirement: The Python requirement can be specified via the `python` or `markers` properties

    For langchain-llm, a possible solution would be to set the `python` property to ">=3.8.1,<4.0"

    https://python-poetry.org/docs/dependency-specification/#python-restricted-dependencies,
    https://python-poetry.org/docs/dependency-specification/#using-environment-markers

From the log above I confused. I think the python version 3.13 does match the requirement of package langchain-llm, as it requires version between 3.8.1 and 4.0.

Any advice would be great appreciated 😄

[Secrus]

Python 3.13 is in range, but your project requirement states >=3.13, which means "everything higher than 3.13", which could mean 3.14, 3.15, 4.0, 6.0, 1000.0, and any other version. This is incompatible with that library, which limits its range to <4.0. The easiest way to fix that is to set your project Python requirement to either 3.13 (no range, bound to a single version) or >=3.13, <4.0 (limit the upper range to be compatible with the library).

[iccfish]

Python 3.13 is in range, but your project requirement states >=3.13, which means "everything higher than 3.13", which could mean 3.14, 3.15, 4.0, 6.0, 1000.0, and any other version. This is incompatible with that library, which limits its range to <4.0. The easiest way to fix that is to set your project Python requirement to either 3.13 (no range, bound to a single version) or >=3.13, <4.0 (limit the upper range to be compatible with the library).

I've tried to modify 3.13 to 3.8, things not changed. However finally I manage to resolve this issue by adding tool.poetry.dependencies.python to pyproject.toml via FAQ. It was a bit odd but it works. For more information: tool.poetry.dependencies