simonfxr/pretty-py.el

Pretty-Py

Pretty-Py allows you to format your Python code using standard tools, currently supports:

• yapf (default)
• autopep8
• black

Why yet another emacs package?

• Unified interface for on the fly switching between different Python code formatters.
• Afaict all of the existing packages just replace your whole buffer which the new formatted content. This packages uses a smart diff mode to only make minimal changes to your buffer (adapted from go-mode.el). This has some a number of advantages, it's faster, it avoids font-locking your whole code a again and has better undo behavior.
• Supports blackd, the http daemon for black, avoiding repeated startup time. Hence this is the recommended option when using the before-save-hook.

Installation and Usage

• Currently you have to fetch it from github, melpa upload pending.
• Make sure your preferred formatter is installed. If it is your path pretty-py will find it, otherwise set pretty-py-{yapf,autopep8,black}-command explicitly.
• If you want to automatically format on every save, enable the minor mode pretty-py-mode from within your python-mode-hook.
• To format your buffer invoke pretty-py-buffer, pretty-py-buffer-yapf, pretty-py-buffer-autopep8 or pretty-py-buffer-black as required.

Example configuration:

(defun my-python-mode-hook ()
  (pretty-py-mode 1))

(use-package pretty-py
  :init
  (add-hook 'python-mode-hook #'my-python-mode-hook)
  :config
  (setq pretty-py-formatter 'black
        pretty-py-use-blackd t
        pretty-py-black-fast-flag t
        pretty-py-black-line-length 79))