Python

Set up a Python project with mise: a requirements.txt project with a virtualenv, a uv project, or scripts with inline dependencies. For installing Python and the virtualenv settings, see Python.

Use a requirements.txt project with a virtualenv

This recipe expects requirements.txt, app.py and a tests/ directory, with pytest in the requirements. mise creates .venv and activates it; the install task fills it with the project's dependencies.

mise.toml

[tools]
python = "3.14"
uv = "latest"
ruff = "latest"

[env]
_.python.venv = { path = ".venv", create = true }

[tasks.install]
description = "Install dependencies"
alias = "i"
run = "uv pip install -r requirements.txt"

[tasks.app]
description = "Run the application"
run = "python app.py"

[tasks.test]
description = "Run tests"
run = "python -m pytest tests/"

[tasks.lint]
description = "Lint the code"
run = "ruff check ."

Run mise run install, then mise run test, mise run lint or mise run app. Add .venv/ to .gitignore. See _.python.venv for its other options.

Use a uv project

This recipe expects a project created by uv init, which writes pyproject.toml and .python-version. mise reads the Python version from .python-version and activates the virtualenv that uv manages:

mise.toml

[tools]
uv = "latest"

[settings]
idiomatic_version_file_enable_tools = ["python"]
python.uv_venv_auto = "create|source"

Run mise install, then mise exec -- uv sync to create uv.lock and .venv. mise finds the uv project through uv.lock, so python.uv_venv_auto has no effect until that file exists. Use "source" instead if only uv should create .venv.

In a shell with mise activated, python resolves to .venv/bin/python at the next prompt. To check without activation:

mise exec -- python -c 'import sys; print(sys.executable)'
# /path/to/project/.venv/bin/python

To have mise run uv sync when pyproject.toml or uv.lock changes, use the experimental mise deps: keep python.uv_venv_auto at "source", set experimental = true under [settings], add [deps.uv], and run mise deps.

Share Python installs with uv

mise sync python --uv makes the Python versions installed by mise and by uv available to both. It shares installed interpreters only: it does not change .python-version, select the project's version, or sync packages. Use uv sync for project dependencies.

Run scripts with inline dependencies

A file task can run with uv run in its shebang and declare its dependencies in a PEP 723 block. uv installs them into a cached environment the first time the script runs:

mise-tasks/print_peps.py

#!/usr/bin/env -S uv run --script
# /// script
# dependencies = ["requests<3", "rich"]
# ///

import requests
from rich.pretty import pprint

resp = requests.get("https://peps.python.org/api/peps.json", timeout=30)
resp.raise_for_status()
data = resp.json()
pprint([(k, v["title"]) for k, v in data.items()][:10])

--script is required when the file name does not end in .py. Declare uv in [tools] as in the uv project recipe, make the file executable with chmod +x mise-tasks/print_peps.py, and run it:

mise run print_peps

[print_peps] $ ~/uv-project/mise-tasks/print_peps.py
Installed 9 packages in 8ms
[
│   ('1', 'PEP Purpose and Guidelines'),
│   ('2', 'Procedure for Adding New Modules'),
    #...
]

The same script also works inline as a run value in mise.toml; see TOML tasks.