Use python-lsp-black instead.

Black plugin for the Python Language Server.

In the same virtualenv as python-language-server:

pip3 install pyls-black

To avoid unexpected results you should make sure yapf and autopep8 are not installed.

• pyls-black can either format an entire file or just the selected text.
• The code will only be formatted if it is syntactically valid Python.
• Text selections are treated as if they were a separate Python file. Unfortunately this means you can't format an indented block of code.
• pyls-black will use your project's pyproject.toml if it has one.

See the wiki for instructions on how to use pyls-black with popular text editors.