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Wing can automatically reformat Python code to be compliant with the PEP 8 Style Guide for Python Code or using the Black, Ruff or YAPF code formatting tools.

Installing Reformatters

Wing uses its own copy of autopep8 for PEP 8 style formatting. If you plan to use Black, Ruff, or YAPF formatting then you must first install the formatter into the Python you are using with your code, with pip or other package manager. For example:

pip install black
pip install ruff
pip install yapf

In Wing Pro, this can also be done with the Packages tool in the Tools menu.

Manual Reformatting

The Source > Reformatting menu contains items for reformatting the current file or selection for PEP 8, or with Black, Ruff, or YAPF. A single Undo will undo the reformatting operation.

Note that reformatting large files may take several minutes, and Wing will lock the file so it cannot be edited during that time. The amount of time spent in reformatting a file is limited to the number of seconds specified with the Editor > Auto-formatting > Reformatting Timeout preference. After the timeout is reached, Wing will abort the reformat process and leave the file unchanged. The default timeout is 5 seconds, to avoid leaving an editor locked for a long period of time.

Reformatting PEP8 selections in locally stored files is not time-limited, so very large selections may lock up the IDE until the reformatting operation completes.

Automatic Reformatting

Wing can auto-format edited lines after the caret leaves the line, or whole files as they are saved to disk. This is enabled with the Auto-Reformat property under the Options tab in Project Properties, or with the Editor > Auto-formatting > Auto-Reformat preference.

The choices are:

  • Disabled turns off all automatic reformatting. This is the default.
  • Lines After Edit reformats individual logical lines (which may span multiple physical lines) after the caret leaves the edited line.
  • Whole Files Before Save reformats whole files when they are saved to disk. This option is recommended only for users with small files, since reformatting larger files may take substantial amounts of time. The process is aborted and the file is saved without reformatting if the time required to reformat it exceeds the Editor > Auto-Formatting > Reformatting Timeout preference.

The formatter to use in auto-formatting can be selected with the Reformatter property under the Options tab in Project Properties, or with the Editor > Auto-formatting > Reformatter preference.

The available reformatters are PEP 8 with autopep8, Black, Ruff, and YAPF.


Wing provides a few commonly used high-level configuration options to control some of the auto-reformatters on the Editor > Auto-formatting preferences page. Other reformatter configuration should be DONE in the reformatter's configuration file. Setting the Reformatter Run Directory property under the Options tab in Project Properties, or the Editor > Auto-formatting > Reformatter Run Directory preference, may be necessary for the reformatter to find its configuration file.


All the reformatters used by Wing assume utf-8 encoding if not otherwise specified in a source file with a PEP 263 Python encoding comment. Whole-file reformatting may fail even if Wing correctly guesses the file's encoding, since the coding comment is the only way to communicate a non-default encoding to the reformatters.

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