Fix unnecessary if checks (#1728)

[etc/vim.git] / docs / editor_integration.md

# Editor integration

## Emacs

Options include the following:

- [purcell/reformatter.el](https://github.com/purcell/reformatter.el)
- [proofit404/blacken](https://github.com/pythonic-emacs/blacken)
- [Elpy](https://github.com/jorgenschaefer/elpy).

## PyCharm/IntelliJ IDEA

1. Install `black`.

```console
$ pip install black
```

2. Locate your `black` installation folder.

On macOS / Linux / BSD:

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

On Windows:

```console
$ 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`.

3. Open External tools in PyCharm/IntelliJ IDEA

On macOS:

`PyCharm -> Preferences -> Tools -> External Tools`

On Windows / Linux / BSD:

`File -> Settings -> Tools -> External Tools`

4. 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: `"$FilePath$"`

5. 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`.

6. Optionally, run _Black_ on every file save:

   1. Make sure you have the
      [File Watchers](https://plugins.jetbrains.com/plugin/7177-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](https://wingware.com/doc/edit/pep8). The detailed procedure is:

1. Install `black`.

```console
$ pip install black
```

2. Make sure it runs from the command line, e.g.

```console
$ black --help
```

3. 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

4. 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](https://github.com/junegunn/vim-plug):

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

or with [Vundle](https://github.com/VundleVim/Vundle.vim):

```
Plugin 'psf/black'
```

and execute the following in a terminal:

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

or you can copy the plugin from
[plugin/black.vim](https://github.com/psf/black/blob/stable/plugin/black.vim).

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

```text
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](https://pythonwheels.com/) 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:

- [regex](https://pypi.org/project/regex/)
- [typed-ast](https://pypi.org/project/typed-ast/)

Now remove those two packages:

```console
$ pip uninstall regex typed-ast -y
```

And now you can install them with:

```console
$ 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:

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

## Visual Studio Code

Use the
[Python extension](https://marketplace.visualstudio.com/items?itemName=ms-python.python)
([instructions](https://code.visualstudio.com/docs/python/editing#_formatting)).

## SublimeText 3

Use [sublack plugin](https://github.com/jgirardet/sublack).

## Jupyter Notebook Magic

Use [blackcellmagic](https://github.com/csurfer/blackcellmagic).

## Python Language Server

If your editor supports the [Language Server Protocol](https://langserver.org/) (Atom,
Sublime Text, Visual Studio Code and many more), you can use the
[Python Language Server](https://github.com/palantir/python-language-server) with the
[pyls-black](https://github.com/rupert/pyls-black) plugin.

## Atom/Nuclide

Use [python-black](https://atom.io/packages/python-black).

## Gradle (the build tool)

Use the [Spotless](https://github.com/diffplug/spotless/tree/main/plugin-gradle) plugin.

## Kakoune

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

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

## Thonny

Use [Thonny-black-code-format](https://github.com/Franccisco/thonny-black-code-format).

## Other integrations

Other editors and tools will require external contributions.

Patches welcome! ✨ 🍰 ✨

Any tool that can pipe code through _Black_ using its stdio mode (just
[use `-` as the file name](https://www.tldp.org/LDP/abs/html/special-chars.html#DASHREF2)).
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](https://www.jetbrains.com/help/pycharm/file-watchers.html).