X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/62bfbd6a63dcac2f6f31eb014f69397c9eb967d2..eb9d0396cd51065c975e366f06dfea60221a2d03:/docs/usage_and_configuration/the_basics.md diff --git a/docs/usage_and_configuration/the_basics.md b/docs/usage_and_configuration/the_basics.md index 6fd8769..533c213 100644 --- a/docs/usage_and_configuration/the_basics.md +++ b/docs/usage_and_configuration/the_basics.md @@ -34,96 +34,161 @@ running `black --help`. Help output -``` - Usage: black [OPTIONS] [SRC]... - - The uncompromising code formatter. - - Options: - -c, --code TEXT Format the code passed in as a string. - -l, --line-length INTEGER How many characters per line to allow. - [default: 88] - - -t, --target-version [py27|py33|py34|py35|py36|py37|py38|py39] - Python versions that should be supported by - Black's output. [default: per-file auto- - detection] - - --pyi Format all input files like typing stubs - regardless of file extension (useful when - piping source on standard input). - - -S, --skip-string-normalization - Don't normalize string quotes or prefixes. - -C, --skip-magic-trailing-comma - Don't use trailing commas as a reason to - split lines. - - --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. - - --color / --no-color Show colored diff. Only applies when - `--diff` is given. - - --fast / --safe If --fast given, skip temporary sanity - checks. [default: --safe] - - --include TEXT A regular expression that matches files and - directories that should be included on - recursive searches. An empty value means - all files are included regardless of the - name. Use forward slashes for directories - on all platforms (Windows, too). Exclusions - are calculated first, inclusions later. - [default: \.pyi?$] - - --exclude TEXT A regular expression that matches files and - directories that should be excluded on - recursive searches. An empty value means no - paths are excluded. Use forward slashes for - directories on all platforms (Windows, too). - Exclusions are calculated first, inclusions - later. [default: /(\.direnv|\.eggs|\.git|\. - hg|\.mypy_cache|\.nox|\.tox|\.venv|venv|\.svn|_bu - ild|buck-out|build|dist)/] - - --extend-exclude TEXT Like --exclude, but adds additional files - and directories on top of the excluded - ones (useful if you simply want to add to - the default). - - --force-exclude TEXT Like --exclude, but files and directories - matching this regex will be excluded even - when they are passed explicitly as - arguments. - - - --stdin-filename TEXT The name of the file when passing it through - stdin. Useful to make sure Black will - respect --force-exclude option on some - editors that rely on using stdin. - - -q, --quiet Don't emit non-error messages to stderr. - Errors are still emitted; silence those with - 2>/dev/null. - - -v, --verbose Also emit messages to stderr about files - that were not changed or were ignored due to - exclusion patterns. - - --version Show the version and exit. - --config FILE Read configuration from FILE path. - -h, --help Show this message and exit. +```{program-output} black --help + ``` +### Code input alternatives + +#### Standard Input + +_Black_ supports formatting code via stdin, with the result being printed to stdout. +Just let _Black_ know with `-` as the path. + +```console +$ echo "print ( 'hello, world' )" | black - +print("hello, world") +reformatted - +All done! ✨ 🍰 ✨ +1 file reformatted. +``` + +**Tip:** if you need _Black_ to treat stdin input as a file passed directly via the CLI, +use `--stdin-filename`. Useful to make sure _Black_ will respect the `--force-exclude` +option on some editors that rely on using stdin. + +#### As a string + +You can also pass code as a string using the `-c` / `--code` option. + +```console +$ black --code "print ( 'hello, world' )" +print("hello, world") +``` + +### Writeback and reporting + +By default _Black_ reformats the files given and/or found in place. Sometimes you need +_Black_ to just tell you what it _would_ do without actually rewriting the Python files. + +There's two variations to this mode that are independently enabled by their respective +flags. Both variations can be enabled at once. + +#### Exit code + +Passing `--check` will make _Black_ exit with: + +- code 0 if nothing would change; +- code 1 if some files would be reformatted; or +- code 123 if there was an internal error + +```console +$ black test.py --check +All done! ✨ 🍰 ✨ +1 file would be left unchanged. +$ echo $? +0 + +$ black test.py --check +would reformat test.py +Oh no! 💥 💔 💥 +1 file would be reformatted. +$ echo $? +1 + +$ black test.py --check +error: cannot format test.py: INTERNAL ERROR: Black produced code that is not equivalent to the source. Please report a bug on https://github.com/psf/black/issues. This diff might be helpful: /tmp/blk_kjdr1oog.log +Oh no! 💥 💔 💥 +1 file would fail to reformat. +$ echo $? +123 +``` + +#### Diffs + +Passing `--diff` will make _Black_ print out diffs that indicate what changes _Black_ +would've made. They are printed to stdout so capturing them is simple. + +If you'd like colored diffs, you can enable them with the `--color`. + +```console +$ black test.py --diff +--- test.py 2021-03-08 22:23:40.848954 +0000 ++++ test.py 2021-03-08 22:23:47.126319 +0000 +@@ -1 +1 @@ +-print ( 'hello, world' ) ++print("hello, world") +would reformat test.py +All done! ✨ 🍰 ✨ +1 file would be reformatted. +``` + +### Output verbosity + +_Black_ in general tries to produce the right amount of output, balancing between +usefulness and conciseness. By default, _Black_ emits files modified and error messages, +plus a short summary. + +```console +$ black src/ +error: cannot format src/black_primer/cli.py: Cannot parse: 5:6: mport asyncio +reformatted src/black_primer/lib.py +reformatted src/blackd/__init__.py +reformatted src/black/__init__.py +Oh no! 💥 💔 💥 +3 files reformatted, 2 files left unchanged, 1 file failed to reformat. +``` + +Passing `-v` / `--verbose` will cause _Black_ to also emit messages about files that +were not changed or were ignored due to exclusion patterns. If _Black_ is using a +configuration file, a blue message detailing which one it is using will be emitted. + +```console +$ black src/ -v +Using configuration from /tmp/pyproject.toml. +src/blib2to3 ignored: matches the --extend-exclude regular expression +src/_black_version.py wasn't modified on disk since last run. +src/black/__main__.py wasn't modified on disk since last run. +error: cannot format src/black_primer/cli.py: Cannot parse: 5:6: mport asyncio +reformatted src/black_primer/lib.py +reformatted src/blackd/__init__.py +reformatted src/black/__init__.py +Oh no! 💥 💔 💥 +3 files reformatted, 2 files left unchanged, 1 file failed to reformat +``` + +Passing `-q` / `--quiet` will cause _Black_ to stop emitting all non-critial output. +Error messages will still be emitted (which can silenced by `2>/dev/null`). + +```console +$ black src/ -q +error: cannot format src/black_primer/cli.py: Cannot parse: 5:6: mport asyncio +``` + +### Versions + +You can check the version of _Black_ you have installed using the `--version` flag. + +```console +$ black --version +black, version 21.10b0 +``` + +An option to require a specific version to be running is also provided. + +```console +$ black --required-version 21.9b0 -c "format = 'this'" +format = "this" +$ black --required-version 31.5b2 -c "still = 'beta?!'" +Oh no! 💥 💔 💥 The required version does not match the running version! +``` + +This is useful for example when running _Black_ in multiple environments that haven't +necessarily installed the correct version. This option can be set in a configuration +file for consistent results across environments. + ## Configuration via a file _Black_ is able to read project-specific default values for its command line options