What Does Not Match This Runtime or Platform
The package (or one of its dependencies) declares a Requires-Python range that excludes the Python interpreter you're using.
Use a compatible runtime, platform, or published build
Use a compatible Python version for the package and create a new venv with it.
If you pinned a version, try a newer/older package version that supports your Python.
Make sure you're using the right interpreter:run python -m pip ... from the same python you want.
If this is in CI, ensure the runner's Python version matches your declared support range.
Why This Runtime or Platform Does Not Match
Usually this comes down to you're using a Python version that is too new (no wheels released yet) or too old for the package, your constraints/pins force a version that doesn't support your interpreter, or you're installing with a different Python than you think (multiple Python installs, wrong venv).
Prove the Runtime and Published Build Now Line Up
Re-run python -m pip install <package> under the compatible Python and confirm pip finds a candidate, and run python -c 'import <module>' to confirm the installed package imports.
Check runtime, platform, and index source
Check your interpreter version:python -V
Run python -m pip install -v <package> and read the Requires-Python messages in verbose output.
If you're in a notebook, ensure the kernel Python matches the environment where you're running pip.
Examples
ERROR: Ignored the following versions that require a different python version: 2.2.0 Requires-Python >=3.8,<3.11
ERROR: Package 'uv-test' requires a different Python: 3.13.2 not in '<3.13,>=3.10'
ERROR: Package 'psychopy' requires a different Python: 3.12.5 not in '<3.11,>=3.8'How pip uses Requires-Python
Packages can declare the Python versions they support via Requires-Python metadata. pip reads that metadata and ignores releases that don't match your interpreter version, even if the version number matches your pin. This commonly happens when using a newer Python than the package supports (or an older Python than required).
Prevent It From Coming Back
To prevent this, pin a project Python version (and enforce it in tooling) to avoid accidental upgrades to unsupported versions, prefer lock/constraints files generated for a specific Python version, and monitor upstream package support for new Python releases before upgrading.
Docs and source code
github.com/pypa/pip/blob/25.3/src/pip/_internal/resolution/resolvelib/factory.py
pip raises UnsupportedPythonVersion with "Package '...' requires a different Python ..." when Requires-Python excludes the current interpreter. - GitHub
if len(causes) == 1:
specifier = str(causes[0].requirement.specifier)
message = (
f"Package {causes[0].parent.name!r} requires a different "
f"Python: {version} not in {specifier!r}"
)
return UnsupportedPythonVersion(message)
github.com/pypa/pip/blob/25.3/src/pip/_internal/resolution/resolvelib/factory.py
pip also logs the filtered candidates with "Ignored the following versions that require a different python version ...". - GitHub
if skipped_by_requires_python:
logger.critical(
"Ignored the following versions that require a different python "
"version: %s",
"; ".join(skipped_by_requires_python) or "none",
)