Python Developer Tools Reference

Reference pages describe each Python development tool: what it does, what it ships with, where it fits in the ecosystem, and which related tools exist. They are meant for quick lookup, not end-to-end reading.

For task-shaped questions, see the How-To guides. For step-by-step setup, see the Tutorials.

The groups below cluster tools by the job they do.

Package & Project Managers

Tools that install dependencies and manage Python projects

conda-pypi

conda-pypi is a conda plugin that installs PyPI packages into conda environments by converting wheels to the .conda format, tracked by conda's solver.

hatch

hatch is a PyPA-maintained Python project manager combining environment management, building, publishing, and version management.

PDM

PDM is a Python package and dependency manager built on the modern PEP 517/518 build-system interface and PEP 621 project metadata in pyproject.toml.

pip

pip is Python's default package installer. Key features, known limitations, and when to consider uv or conda as alternatives.

pipenv

pipenv combines pip and virtualenv into a single CLI for managing Python application dependencies with automatic virtual environments and a Pipfile-based lockfile workflow.

poetry

Poetry is a Python packaging and dependency management tool handling installation, environments, building, and publishing via pyproject.toml.

uv

uv is a high-performance Python package and project manager that unifies dependency management, environment creation, code formatting, and version control.

Scientific Python

conda-family tools for data science, ML, and CUDA workflows

Anaconda

Anaconda Distribution is a Python and R data science platform bundling conda, pre-installed scientific libraries, and GUI tools.

Conda

conda is a language-agnostic package and environment manager used primarily in scientific computing and data science.

Conda Package

A conda package is a compressed archive containing pre-built binaries, metadata, and dependency information for distribution through conda channels.

conda-forge

conda-forge is a community-maintained channel of conda packages, offering a free alternative to the commercial Anaconda channel with over 25,000 feedstocks.

pixi

Pixi is a cross-platform package manager and workflow tool that provides access to conda channels alongside PyPI, with project-local environments and a built-in task runner.

Linters & Formatters

Tools that lint and format Python source code

Black

Black is an opinionated Python code formatter that enforces a strict subset of PEP 8 with minimal configuration options.

flake8

Flake8 combines PyFlakes, pycodestyle, and mccabe into a single Python linting tool, now largely superseded by Ruff.

prek

prek is a fast drop-in replacement for pre-commit that runs faster, uses less disk, and needs no Python dependency.

pylint

Pylint is a Python static analysis tool that catches errors and design problems beyond what style-focused linters check, including duplicate code and cyclomatic complexity.

pyproject-fmt

pyproject-fmt is an opinionated formatter for pyproject.toml that sorts dependencies, normalizes version specifiers, reorders tables, and generates Python version classifiers.

ruff

Ruff is a fast Python linter and formatter that replaces flake8, Black, isort, and pyupgrade. Features, installation, pros and cons vs pylint.

Type Checkers

Static type checkers for Python

basedpyright

Basedpyright is a community fork of Microsoft's pyright that re-implements Pylance-exclusive features outside VS Code, ships directly to PyPI without a Node.js dependency, and enables all diagnostic rules by default.

mypy

mypy is the original Python static type checker. Pros, cons, configuration options, and how it compares to Pyright and ty.

pyrefly

Pyrefly is a Rust-based static type checker and language server for Python, developed by Meta, with aggressive type inference and IDE features.

pyright

pyright is Microsoft's fast static type checker for Python, powering VS Code's Pylance extension with real-time type analysis, autocompletion, and code navigation.

ty

ty is a Python type checker and language server from OpenAI. Features, configuration, IDE integration, and how it compares to mypy and Pyright.

zuban

Zuban is a fast Rust-based Python type checker and language server from the author of Jedi. It ships a mypy-compatible mode and a pyright-style mode, and is dual-licensed under AGPL-3.0 and a paid commercial license.

Test Runners

Frameworks and orchestrators for running Python tests

nox

nox is a Python test automation tool that uses Python code for configuration to run tests across multiple versions and environments, with uv backend support and pyproject.toml integration.

pytest

pytest is a Python testing framework with concise syntax, powerful fixtures, parameterized testing, and a rich plugin ecosystem.

tox-uv

tox-uv is a tox plugin that replaces pip and virtualenv with uv for faster environment creation and dependency installation.

tox

tox is a testing automation tool that manages virtual environments and runs tests across multiple Python versions, configured in tox.toml, pyproject.toml, or tox.ini.

Python Versions & Virtualenvs

Tools for installing Python interpreters and creating virtual environments

pyenv-virtualenv

pyenv-virtualenv is a pyenv plugin for creating and auto-activating virtual environments tied to specific Python versions.

pyenv

pyenv is a command-line tool for installing, managing, and switching between multiple Python interpreter versions on macOS and Linux.

venv

venv is Python's built-in module for creating virtual environments. How to create, activate, and use venv vs virtualenv and uv.

virtualenv

virtualenv is a third-party tool for creating isolated Python environments with their own interpreter and packages.

Build & Publishing

Build backends, frontends, and tools for distributing Python packages

Briefcase

Briefcase packages Python apps for iOS, Android, macOS, Windows, Linux, and Web from a single pyproject.toml config. Part of BeeWare.

build

build is PyPA's PEP 517-compliant frontend tool for building Python packages using any standards-compliant build backend.

cibuildwheel

cibuildwheel is a CI tool that automates building Python wheels across multiple operating systems, architectures, and Python versions for distribution.

cx_Freeze

cx_Freeze freezes Python apps into native installers (MSI, DMG, AppImage, deb, rpm) for Windows, macOS, and Linux from one config.

distutils

distutils was Python's original standard library module for building and distributing packages, deprecated in Python 3.10 and removed in Python 3.12.

Flit

Flit is a lightweight Python packaging tool for building and publishing pure-Python packages. Its flit-core build backend carries zero runtime dependencies.

Nuitka

Nuitka compiles Python source to C and links against libpython, producing standalone native executables for Windows, macOS, and Linux.

PyInstaller

PyInstaller bundles a Python app and the CPython interpreter into a single distributable for Windows, macOS, and Linux. No runtime Python needed.

sdist

An sdist (source distribution) is a Python package format containing raw source code that may need building during installation.

setup.cfg

setup.cfg is an INI-style configuration file for setuptools that holds project metadata, dependencies, and build options in a declarative form. It predates pyproject.toml's [project] table and is now considered legacy for metadata, though still valid for setuptools-specific options and tool configuration.

setuptools

setuptools is Python's original and most established build backend for building, distributing, and installing packages.

Twine

Twine uploads Python packages to PyPI and other indexes with secure authentication and TLS verification, handling credentials safely.

Wheel

A wheel is a pre-built binary distribution format for Python packages, defined by PEP 427, enabling fast installation.

Standards & Supporting Tools

pyproject.toml, requirements.txt, pipx, IPython, and the rest of the supporting cast

Cookiecutter

Cookiecutter is a command-line tool that creates project structures from templates using Jinja2 variable replacement.

direnv

direnv loads and unloads environment variables based on the current directory, useful for activating Python virtual environments and exporting per-project settings without polluting the global shell.

Furo

Furo is a clean, customisable Sphinx theme with built-in light and dark modes, used by pip, attrs, and many smaller Python projects.

homebrew

Homebrew is a macOS and Linux package manager that can install Python tools and dependencies, though not recommended for Python development.

IPython

IPython is an enhanced interactive Python interpreter with syntax highlighting, tab completion, magic commands, and Jupyter kernel support.

marimo

marimo is a reactive Python notebook stored as a plain .py file. Cells re-run automatically when their inputs change, and PEP 723 inline metadata lets uv launch notebooks in isolated environments.

Material for MkDocs

Material for MkDocs is a theme for MkDocs that adds search, dark mode, code annotations, and a wide configuration surface, used by FastAPI, Typer, and SQLModel.

MkDocs

MkDocs is a static site generator that builds project documentation from Markdown source files and a single YAML configuration file.

mkdocstrings

mkdocstrings is a MkDocs plugin that injects API documentation generated from source code (Python, C, TypeScript, and more) into Markdown pages.

pdb

pdb is Python's standard-library interactive debugger. Use `breakpoint()` to enter, step through code, inspect variables, and customize behavior via `~/.pdbrc`.

pip-tools

pip-tools provides pip-compile for resolving and locking dependencies and pip-sync for synchronizing environments to lockfiles.

Pipfile

Pipfile is a TOML-based dependency declaration format used by Pipenv as a replacement for requirements.txt.

pipx

pipx installs Python CLI tools in isolated virtual environments so their dependencies never conflict. How it compares to uv tool and pip.

pyproject.toml

pyproject.toml is the standard config file for Python projects, holding metadata, dependencies, build-system settings, and tool config.

Python Packaging User Guide

The Python Packaging User Guide (PyPUG) is the official documentation for packaging, publishing, and installing Python projects using tools maintained by the Python Packaging Authority.

Read the Docs

Read the Docs is a hosted documentation platform that builds, versions, and serves project documentation automatically whenever code is pushed to a Git repository.

requirements.txt

requirements.txt is a plain-text format for declaring Python package dependencies, used by pip, uv, and pip-tools as deployment artifacts or lockfiles.

sphinx-autobuild

sphinx-autobuild watches a Sphinx documentation source tree and rebuilds the HTML on every change, refreshing the browser automatically.

Sphinx

Sphinx is a documentation generator that turns reStructuredText or Markdown source files into HTML, PDF, ePub, and other formats. It is the default doc tool for CPython and most of the scientific Python ecosystem.

uvx

uvx runs Python command-line tools in temporary isolated environments without installing them permanently. It is an alias for uv tool run.

watchfiles

watchfiles is a Python library and CLI for filesystem monitoring, backed by Rust's notify crate. It powers uvicorn's --reload mode and provides both synchronous and asynchronous APIs for watching files and restarting processes on changes.

Profilers

Sampling and deterministic profilers for CPU, memory, and GPU code

profiling.sampling

profiling.sampling is the statistical sampling profiler that ships with Python 3.15. It attaches to a running process by PID, samples at up to 1 MHz, and writes flame graphs, pstats, or interactive HTML.

py-spy

py-spy is a low-overhead sampling profiler for Python that attaches to a running process without code changes or restarts.