File collection and discovery¶
You can directly pass Black files, but you can also pass directories and Black will walk them, collecting files to format. It determines what files to format or skip automatically using the inclusion and exclusion regexes and as well their modification time.
Ignoring unmodified files¶
Black remembers files it has already formatted, unless the --diff
flag is used or
code is passed via standard input. This information is stored per-user. The exact
location of the file depends on the Black version and the system on which Black is
run. The file is non-portable. The standard location on common operating systems is:
Windows:
C:\\Users\<username>\AppData\Local\black\black\Cache\<version>\cache.<line-length>.<file-mode>.pickle
macOS:
/Users/<username>/Library/Caches/black/<version>/cache.<line-length>.<file-mode>.pickle
Linux:
/home/<username>/.cache/black/<version>/cache.<line-length>.<file-mode>.pickle
file-mode
is an int flag that determines whether the file was formatted as 3.6+ only,
as .pyi, and whether string normalization was omitted.
To override the location of these files on macOS or Linux, set the environment variable
XDG_CACHE_HOME
to your preferred location. For example, if you want to put the cache
in the directory you’re running Black from, set XDG_CACHE_HOME=.cache
. Black will
then write the above files to .cache/black/<version>/
.
.gitignore¶
If --exclude
is not set, Black will automatically ignore files and directories in
.gitignore
file, if present. The .gitignore
file must be in the project root to be
used and nested .gitignore
aren’t supported.
If you want Black to continue using .gitignore
while also configuring the exclusion
rules, please use --extend-exclude
.