yapf

Format a Python file and print to stdout

$ yapf [file.py]

$ yapf -i [file.py]

$ yapf -d [file.py]

$ yapf --style=google [file.py]

$ yapf -r -i [directory/]

$ yapf -p -r -i [directory/]

$ yapf --style-help

$ yapf --style='{based_on_style: pep8, indent_width: 4}' [file.py]

yapf [options] [files...]

yapf (Yet Another Python Formatter) is a Python code formatter developed by Google. Unlike linters that only warn about style violations, yapf reformats code to match the configured style, producing consistent output regardless of the original formatting.
The algorithm analyzes code structure and calculates optimal formatting based on the configured style. Built-in styles include pep8 (default), google, chromium, and facebook. Custom styles can be defined by inheriting from a base style and overriding specific options.
Configuration files (.style.yapf, setup.cfg, or pyproject.toml) in the source directory or parent directories are automatically detected. The config file uses INI format with a [style] section.
yapf can format specific line ranges with --lines, useful for formatting only changed code in version control workflows.

-i, --in-place

Modify files in place

Print diff of changes without modifying files

Recursively format files in directories

Run formatting in parallel for multiple files

Style: pep8, google, chromium, facebook, or path to config file

Show documentation for all style options

Format only specified lines (e.g., 1-10,15-20)

Exclude files matching pattern

Show version and exit

yapf may produce different output than other formatters like black. The -i option modifies files directly; use -d first to preview changes. Some complex expressions may be formatted in unexpected ways. Comments can affect formatting decisions.

yapf was developed at Google and first released in 2015 as an open-source project. It was inspired by clang-format (for C/C++), applying similar algorithmic formatting to Python. The name follows the Unix tradition of "Yet Another" tools, acknowledging the existence of other Python formatters.

black(1), autopep8(1), isort(1), flake8(1)