black man page

• Auto-format a file or entire directory: black path/to/file_or_directory
• Format the code passed in as a string: black -c path/to/file_or_directory
• Output a diff for each file on stdout: black --diff path/to/file_or_directory
• Return the status without writing the files back: black --check path/to/file_or_directory
• Auto-format a file or directory emitting exclusively error messages to stderr: black --quiet path/to/file_or_directory

tldr.sh

black [Options] [SRC]...

The uncompromising code formatter.

-l, --line-length INTEGER

How many character per line to allow.  [default: 88]

--check

Don't write the files back, just return the status.  Return code 0 means nothing would change.  Return code 1 means some files would be reformatted.  Return code 123 means there was an internal error.

--diff

Don't write the files back, just output a diff for each file on stdout.

--fast / --safe

If --fast given, skip temporary sanity checks. [default: --safe]

-q, --quiet

Don't emit non-error messages to stderr. Errors are still emitted, silence those with 2>/dev/null.

--version

Show the version and exit.