Editor integration

Emacs

Options include the following:

PyCharm/IntelliJ IDEA

  1. Install black.
$ pip install black
  1. Locate your black installation folder.

On macOS / Linux / BSD:

$ which black
/usr/local/bin/black  # possible location

On Windows:

$ where black
%LocalAppData%\Programs\Python\Python36-32\Scripts\black.exe  # possible location

Note that if you are using a virtual environment detected by PyCharm, this is an unneeded step. In this case the path to black is $PyInterpreterDirectory$/black.

  1. Open External tools in PyCharm/IntelliJ IDEA

On macOS:

PyCharm -> Preferences -> Tools -> External Tools

On Windows / Linux / BSD:

File -> Settings -> Tools -> External Tools

  1. Click the + icon to add a new external tool with the following values:

    • Name: Black
    • Description: Black is the uncompromising Python code formatter.
    • Program: <install_location_from_step_2>
    • Arguments: "$FilePath$"

  2. Format the currently opened file by selecting Tools -> External Tools -> black.

    • Alternatively, you can set a keyboard shortcut by navigating to Preferences or Settings -> Keymap -> External Tools -> External Tools - Black.

  3. Optionally, run Black on every file save:

    1. Make sure you have the File Watchers plugin installed.
    2. Go to Preferences or Settings -> Tools -> File Watchers and click + to add a new watcher:
      • Name: Black
      • File type: Python
      • Scope: Project Files
      • Program: <install_location_from_step_2>
      • Arguments: $FilePath$
      • Output paths to refresh: $FilePath$
      • Working directory: $ProjectFileDir$
    • Uncheck “Auto-save edited files to trigger the watcher” in Advanced Options

Wing IDE

Wing supports black via the OS Commands tool, as explained in the Wing documentation on pep8 formatting. The detailed procedure is:

  1. Install black.
$ pip install black
  1. Make sure it runs from the command line, e.g.
$ black --help
  1. In Wing IDE, activate the OS Commands panel and define the command black to execute black on the currently selected file:
  • Use the Tools -> OS Commands menu selection
  • click on + in OS Commands -> New: Command line..
    • Title: black
    • Command Line: black %s
    • I/O Encoding: Use Default
    • Key Binding: F1
    • [x] Raise OS Commands when executed
    • [x] Auto-save files before execution
    • [x] Line mode
  1. Select a file in the editor and press F1 , or whatever key binding you selected in step 3, to reformat the file.

Vim

Commands and shortcuts:

  • :Black to format the entire file (ranges not supported);
  • :BlackUpgrade to upgrade Black inside the virtualenv;
  • :BlackVersion to get the current version of Black inside the virtualenv.

Configuration:

  • g:black_fast (defaults to 0)
  • g:black_linelength (defaults to 88)
  • g:black_skip_string_normalization (defaults to 0)
  • g:black_virtualenv (defaults to ~/.vim/black or ~/.local/share/nvim/black)

To install with vim-plug:

Plug 'psf/black', { 'branch': 'stable' }

or with Vundle:

Plugin 'psf/black'

and execute the following in a terminal:

$ cd ~/.vim/bundle/black
$ git checkout origin/stable -b stable

or you can copy the plugin from plugin/black.vim.

mkdir -p ~/.vim/pack/python/start/black/plugin
curl https://raw.githubusercontent.com/psf/black/master/plugin/black.vim -o ~/.vim/pack/python/start/black/plugin/black.vim

Let me know if this requires any changes to work with Vim 8’s builtin packadd, or Pathogen, and so on.

This plugin requires Vim 7.0+ built with Python 3.6+ support. It needs Python 3.6 to be able to run Black inside the Vim process which is much faster than calling an external command.

On first run, the plugin creates its own virtualenv using the right Python version and automatically installs Black. You can upgrade it later by calling :BlackUpgrade and restarting Vim.

If you need to do anything special to make your virtualenv work and install Black (for example you want to run a version from master), create a virtualenv manually and point g:black_virtualenv to it. The plugin will use it.

To run Black on save, add the following line to .vimrc or init.vim:

autocmd BufWritePre *.py execute ':Black'

To run Black on a key press (e.g. F9 below), add this:

nnoremap <F9> :Black<CR>

How to get Vim with Python 3.6? On Ubuntu 17.10 Vim comes with Python 3.6 by default. On macOS with Homebrew run: brew install vim. When building Vim from source, use: ./configure --enable-python3interp=yes. There’s many guides online how to do this.

I get an import error when using Black from a virtual environment: If you get an error message like this:

Traceback (most recent call last):
  File "<string>", line 63, in <module>
  File "/home/gui/.vim/black/lib/python3.7/site-packages/black.py", line 45, in <module>
    from typed_ast import ast3, ast27
  File "/home/gui/.vim/black/lib/python3.7/site-packages/typed_ast/ast3.py", line 40, in <module>
    from typed_ast import _ast3
ImportError: /home/gui/.vim/black/lib/python3.7/site-packages/typed_ast/_ast3.cpython-37m-x86_64-linux-gnu.so: undefined symbool: PyExc_KeyboardInterrupt

Then you need to install typed_ast and regex directly from the source code. The error happens because pip will download Python wheels if they are available. Python wheels are a new standard of distributing Python packages and packages that have Cython and extensions written in C are already compiled, so the installation is much more faster. The problem here is that somehow the Python environment inside Vim does not match with those already compiled C extensions and these kind of errors are the result. Luckily there is an easy fix: installing the packages from the source code.

The two packages that cause the problem are:

Now remove those two packages:

$ pip uninstall regex typed-ast -y

And now you can install them with:

$ pip install --no-binary :all: regex typed-ast

The C extensions will be compiled and now Vim’s Python environment will match. Note that you need to have the GCC compiler and the Python development files installed (on Ubuntu/Debian do sudo apt-get install build-essential python3-dev).

If you later want to update Black, you should do it like this:

$ pip install -U black --no-binary regex,typed-ast

Visual Studio Code

Use the Python extension (instructions).

SublimeText 3

Use sublack plugin.

Jupyter Notebook Magic

Use blackcellmagic.

Python Language Server

If your editor supports the Language Server Protocol (Atom, Sublime Text, Visual Studio Code and many more), you can use the Python Language Server with the pyls-black plugin.

Atom/Nuclide

Use python-black.

Kakoune

Add the following hook to your kakrc, then run Black with :format.

hook global WinSetOption filetype=python %{
    set-option window formatcmd 'black -q  -'
}

Other editors

Other editors will require external contributions.

Patches welcome! ✨ 🍰 ✨

Any tool that can pipe code through Black using its stdio mode (just use - as the file name). The formatted code will be returned on stdout (unless --check was passed). Black will still emit messages on stderr but that shouldn’t affect your use case.

This can be used for example with PyCharm’s or IntelliJ’s File Watchers.