Install a specific Python package version with pip

Use python -m pip install "package==version" to request an exact version. A different installed version can be replaced by the same command, including when the requested version is older. You normally do not need to uninstall it first or force a reinstall.

Express the version policy

python -m pip install "requests==2.31.0"
python -m pip install "requests>=2.28,<3.0"
python -m pip install "requests~=2.31.0"
python -m pip install "requests>=2.0"

These are syntax examples using historical versions, not recommendations to deploy those releases. Quote specifiers so the shell does not interpret comparison characters as redirection.

For normal final releases, ~=2.31.0 allows 2.31 patch releases from 2.31.0 onward and excludes 2.32.0. The number of version components matters: ~=2.31 permits later 2.x releases. Python packaging's rules also cover pre-releases, post-releases, and local versions; do not assume another package manager's operator is identical.

Check the environment and available candidates

python -m pip --version
python -m pip index versions requests

The version list reflects the configured index and compatibility filters. It is not necessarily every release published anywhere. Use a virtual environment and the intended Python interpreter before installing.

After changing a version:

python -m pip install "requests==2.31.0"
python -m pip check

pip check detects declared dependency conflicts. It does not test application behavior, optional features, or API compatibility.

Put constraints in a requirements file

requests==2.31.0
flask>=3.0,<4.0
numpy~=1.26.4

Exact direct pins do not fully pin transitive dependencies; ranges can resolve differently later. Reproducible deployment also depends on the interpreter, platform, indexes, and artifacts. A lock-generation workflow, hashes, and retained artifacts can strengthen that process; pip freeze is only a snapshot of one installed environment.

FAQ

Why does pip report No matching distribution found?

Check the package/version spelling, index access, required Python version, platform tags, and binary/source selection options. A compiler error generally occurs later, after pip has selected source to build. A missing compiler is not the generic explanation for “no matching distribution.”

Does --upgrade override an exact pin?

No. The requested version must still satisfy the pin. --upgrade is usually unnecessary for changing the named package to an exact version; it also interacts with dependency-upgrade strategy, so avoid assuming every combination has identical effects on dependencies.

What if another package requires an incompatible version?

Resolve the conflicting requirements together. Tools such as pip-tools, uv, or Poetry can help compute and record a compatible environment, but no lock file can make contradictory requirements compatible. Test the resulting environment before deployment.

References: pip install, Python package version specifiers, pip dependency resolution.