From 611737f9cc186d3e6463ef774fdbda4f77055d4c Mon Sep 17 00:00:00 2001 From: =?utf8?q?=C5=81ukasz=20Langa?= Date: Mon, 26 Mar 2018 18:37:36 -0700 Subject: [PATCH] Big documentation deduplication Most is not generated from README.md so we no longer have to remember to update two Change Logs, and so on! If we decide to diverge from the README in Sphinx, that's fine, too. We will just create dedicated documents. --- README.md | 107 +++++++++++++-------- docs/authors.md | 1 + docs/change_log.md | 1 + docs/changelog.md | 93 ------------------ docs/conf.py | 44 +++++++++ docs/contributing_to_black.md | 1 + docs/editor_integration.md | 1 + docs/index.rst | 10 +- docs/installation_and_usage.md | 1 + docs/license.md | 1 + docs/requirements-docs.txt | 2 - docs/show_your_style.md | 1 + docs/technical_philosophy.md | 167 --------------------------------- docs/testimonials.md | 1 + docs/the_black_code_style.md | 1 + docs/usage.md | 64 ------------- 16 files changed, 129 insertions(+), 367 deletions(-) create mode 120000 docs/authors.md create mode 120000 docs/change_log.md delete mode 100644 docs/changelog.md create mode 120000 docs/contributing_to_black.md create mode 120000 docs/editor_integration.md create mode 120000 docs/installation_and_usage.md create mode 120000 docs/license.md delete mode 100644 docs/requirements-docs.txt create mode 120000 docs/show_your_style.md delete mode 100644 docs/technical_philosophy.md create mode 120000 docs/testimonials.md create mode 120000 docs/the_black_code_style.md delete mode 100644 docs/usage.md diff --git a/README.md b/README.md index d74d436..1cd1ef0 100644 --- a/README.md +++ b/README.md @@ -27,33 +27,28 @@ content instead. possible. -## NOTE: This is an early pre-release +## Installation and Usage -*Black* can already successfully format itself and the standard library. -It also sports a decent test suite. However, it is still very new. -Things will probably be wonky for a while. This is made explicit by the -"Alpha" trove classifier, as well as by the "a" in the version number. -What this means for you is that **until the formatter becomes stable, -you should expect some formatting to change in the future**. - -Also, as a temporary safety measure, *Black* will check that the -reformatted code still produces a valid AST that is equivalent to the -original. This slows it down. If you're feeling confident, use -``--fast``. - - -## Installation +### Installation *Black* can be installed by running `pip install black`. It requires Python 3.6.0+ to run but you can reformat Python 2 code with it, too. -*Black* is able to parse all of the new syntax supported on Python 3.6 -but also *effectively all* the Python 2 syntax at the same time. -## Usage +### Usage +To get started right away with sensible defaults: ``` +black {source_file_or_directory} +``` + +### Command line options + +Black doesn't provide many options. You can list them by running +`black --help`: + +```text black [OPTIONS] [SRC]... Options: @@ -78,7 +73,22 @@ Options: used). -## The philosophy behind *Black* +### NOTE: This is an early pre-release + +*Black* can already successfully format itself and the standard library. +It also sports a decent test suite. However, it is still very new. +Things will probably be wonky for a while. This is made explicit by the +"Alpha" trove classifier, as well as by the "a" in the version number. +What this means for you is that **until the formatter becomes stable, +you should expect some formatting to change in the future**. + +Also, as a temporary safety measure, *Black* will check that the +reformatted code still produces a valid AST that is equivalent to the +original. This slows it down. If you're feeling confident, use +``--fast``. + + +## The *Black* code style *Black* reformats entire files in place. It is not configurable. It doesn't take previous formatting into account. It doesn't reformat @@ -87,12 +97,13 @@ recognizes [YAPF](https://github.com/google/yapf)'s block comments to the same effect, as a courtesy for straddling code. -### How *Black* formats files +### How *Black* wraps lines *Black* ignores previous formatting and applies uniform horizontal and vertical whitespace to your code. The rules for horizontal whitespace are pretty obvious and can be summarized as: do whatever -makes `pycodestyle` happy. +makes `pycodestyle` happy. The coding style used by *Black* can be +viewed as a strict subset of PEP 8. As for vertical whitespace, *Black* tries to render one full expression or simple statement per line. If this fits the allotted line length, @@ -160,20 +171,6 @@ between two distinct sections of the code that otherwise share the same indentation level (like the arguments list and the docstring in the example above). -Unnecessary trailing commas are removed if an expression fits in one -line. This makes it 1% more likely that your line won't exceed the -allotted line length limit. - -*Black* avoids spurious vertical whitespace. This is in the spirit of -PEP 8 which says that in-function vertical whitespace should only be -used sparingly. One exception is control flow statements: *Black* will -always emit an extra empty line after ``return``, ``raise``, ``break``, -``continue``, and ``yield``. This is to make changes in control flow -more prominent to readers of your code. - -That's it. The rest of the whitespace formatting rules follow PEP 8 and -are designed to keep `pycodestyle` quiet. - ### Line length @@ -214,6 +211,13 @@ bother you if you overdo it by a few km/h". ### Empty lines +*Black* avoids spurious vertical whitespace. This is in the spirit of +PEP 8 which says that in-function vertical whitespace should only be +used sparingly. One exception is control flow statements: *Black* will +always emit an extra empty line after ``return``, ``raise``, ``break``, +``continue``, and ``yield``. This is to make changes in control flow +more prominent to readers of your code. + *Black* will allow single empty lines left by the original editors, except when they're added within parenthesized expressions. Since such expressions are always reformatted to fit minimal space, this whitespace @@ -228,7 +232,36 @@ entire function, use a docstring or put a leading comment in the function body. -### Editor integration +### Trailing commas + +*Black* will add trailing commas to expressions that are split +by comma where each element is on its own line. This includes function +signatures. + +Unnecessary trailing commas are removed if an expression fits in one +line. This makes it 1% more likely that your line won't exceed the +allotted line length limit. Moreover, in this scenario, if you added +another argument to your call, you'd probably fit it in the same line +anyway. That doesn't make diffs any larger. + +One exception to removing trailing commas is tuple expressions with +just one element. In this case *Black* won't touch the single trailing +comma as this would unexpectedly change the underlying data type. Note +that this is also the case when commas are used while indexing. This is +a tuple in disguise: ```numpy_array[3, ]```. + +One exception to adding trailing commas is function signatures +containing `*`, `*args`, or `**kwargs`. In this case a trailing comma +is only safe to use on Python 3.6. *Black* will detect if your file is +already 3.6+ only and use trailing commas in this situation. If you +wonder how it knows, it looks for f-strings and existing use of trailing +commas in function signatures that have stars in them. In other words, +if you'd like a trailing comma in this situation and *Black* didn't +recognize it was safe to do so, put it there manually and *Black* will +keep it. + + +## Editor integration * Visual Studio Code: [joslarson.black-vscode](https://marketplace.visualstudio.com/items?itemName=joslarson.black-vscode) * Emacs: [proofit404/blacken](https://github.com/proofit404/blacken) @@ -282,7 +315,7 @@ Looks like this: [![Code style: black](https://img.shields.io/badge/code%20style MIT -## Contributing +## Contributing to Black In terms of inspiration, *Black* is about as configurable as *gofmt* and *rustfmt* are. This is deliberate. diff --git a/docs/authors.md b/docs/authors.md new file mode 120000 index 0000000..704a421 --- /dev/null +++ b/docs/authors.md @@ -0,0 +1 @@ +/Users/ambv/Dropbox (Personal)/Python/black/docs/_build/generated/authors.md \ No newline at end of file diff --git a/docs/change_log.md b/docs/change_log.md new file mode 120000 index 0000000..36bf3dc --- /dev/null +++ b/docs/change_log.md @@ -0,0 +1 @@ +/Users/ambv/Dropbox (Personal)/Python/black/docs/_build/generated/change_log.md \ No newline at end of file diff --git a/docs/changelog.md b/docs/changelog.md deleted file mode 100644 index af78900..0000000 --- a/docs/changelog.md +++ /dev/null @@ -1,93 +0,0 @@ -## Change Log - -### 18.3a4 - -* `# fmt: off` and `# fmt: on` are implemented (#5) - -* automatic detection of deprecated Python 2 forms of print statements - and exec statements in the formatted file (#49) - -* use proper spaces for complex expressions in default values of typed - function arguments (#60) - -* only return exit code 1 when --check is used (#50) - -* don't remove single trailing commas from square bracket indexing - (#59) - -* don't omit whitespace if the previous factor leaf wasn't a math - operator (#55) - -* omit extra space in kwarg unpacking if it's the first argument (#46) - -* omit extra space in [Sphinx auto-attribute comments](http://www.sphinx-doc.org/en/stable/ext/autodoc.html#directive-autoattribute) - (#68) - - -### 18.3a3 - -* don't remove single empty lines outside of bracketed expressions - (#19) - -* added ability to pipe formatting from stdin to stdin (#25) - -* restored ability to format code with legacy usage of `async` as - a name (#20, #42) - -* even better handling of numpy-style array indexing (#33, again) - - -### 18.3a2 - -* changed positioning of binary operators to occur at beginning of lines - instead of at the end, following [a recent change to PEP8](https://github.com/python/peps/commit/c59c4376ad233a62ca4b3a6060c81368bd21e85b) - (#21) - -* ignore empty bracket pairs while splitting. This avoids very weirdly - looking formattings (#34, #35) - -* remove a trailing comma if there is a single argument to a call - -* if top level functions were separated by a comment, don't put four - empty lines after the upper function - -* fixed unstable formatting of newlines with imports - -* fixed unintentional folding of post scriptum standalone comments - into last statement if it was a simple statement (#18, #28) - -* fixed missing space in numpy-style array indexing (#33) - -* fixed spurious space after star-based unary expressions (#31) - - -### 18.3a1 - -* added `--check` - -* only put trailing commas in function signatures and calls if it's - safe to do so. If the file is Python 3.6+ it's always safe, otherwise - only safe if there are no `*args` or `**kwargs` used in the signature - or call. (#8) - -* fixed invalid spacing of dots in relative imports (#6, #13) - -* fixed invalid splitting after comma on unpacked variables in for-loops - (#23) - -* fixed spurious space in parenthesized set expressions (#7) - -* fixed spurious space after opening parentheses and in default - arguments (#14, #17) - -* fixed spurious space after unary operators when the operand was - a complex expression (#15) - - -### 18.3a0 - -* first published version, Happy 🍰 Day 2018! - -* alpha quality - -* date-versioned (see: https://calver.org/) diff --git a/docs/conf.py b/docs/conf.py index 5d0e9e3..6edddba 100644 --- a/docs/conf.py +++ b/docs/conf.py @@ -15,6 +15,7 @@ import ast from pathlib import Path import re +import shutil import string from recommonmark.parser import CommonMarkParser @@ -40,6 +41,48 @@ def make_pypi_svg(version): f.write(svg) +def make_filename(line): + non_letters = re.compile(r'[^a-z]+') + filename = line[3:].rstrip().lower() + filename = non_letters.sub('_', filename) + if filename.startswith('_'): + filename = filename[1:] + if filename.endswith('_'): + filename = filename[:-1] + return filename + '.md' + + +def generate_sections_from_readme(): + target_dir = CURRENT_DIR / '_build' / 'generated' + readme = CURRENT_DIR / '..' / 'README.md' + shutil.rmtree(str(target_dir), ignore_errors=True) + target_dir.mkdir(parents=True) + + output = None + with open(str(readme), 'r', encoding='utf8') as f: + for line in f: + if line.startswith('## '): + if output is not None: + output.close() + filename = make_filename(line) + output_path = CURRENT_DIR / filename + if output_path.is_symlink() or output_path.is_file(): + output_path.unlink() + output_path.symlink_to(target_dir / filename) + output = open(str(output_path), 'w', encoding='utf8') + output.write( + '[//]: # (NOTE: THIS FILE IS AUTOGENERATED FROM README.md)\n\n' + ) + + if output is None: + continue + + if line.startswith('##'): + line = line[1:] + + output.write(line) + + # -- Project information ----------------------------------------------------- project = 'Black' @@ -54,6 +97,7 @@ version = release for sp in 'abcfr': version = version.split(sp)[0] make_pypi_svg(release) +generate_sections_from_readme() # -- General configuration --------------------------------------------------- diff --git a/docs/contributing_to_black.md b/docs/contributing_to_black.md new file mode 120000 index 0000000..079bd4a --- /dev/null +++ b/docs/contributing_to_black.md @@ -0,0 +1 @@ +/Users/ambv/Dropbox (Personal)/Python/black/docs/_build/generated/contributing_to_black.md \ No newline at end of file diff --git a/docs/editor_integration.md b/docs/editor_integration.md new file mode 120000 index 0000000..e234140 --- /dev/null +++ b/docs/editor_integration.md @@ -0,0 +1 @@ +/Users/ambv/Dropbox (Personal)/Python/black/docs/_build/generated/editor_integration.md \ No newline at end of file diff --git a/docs/index.rst b/docs/index.rst index 7a0995b..9422402 100644 --- a/docs/index.rst +++ b/docs/index.rst @@ -16,7 +16,7 @@ can focus on the content instead. .. note:: - `Black is an early pre-release `_. + `Black is an early pre-release `_. Testimonials @@ -46,10 +46,12 @@ Contents .. toctree:: :maxdepth: 2 - usage - technical_philosophy + installation_and_usage + the_black_code_style + editor_integration contributing - changelog + change_log + authors Indices and tables diff --git a/docs/installation_and_usage.md b/docs/installation_and_usage.md new file mode 120000 index 0000000..64caa30 --- /dev/null +++ b/docs/installation_and_usage.md @@ -0,0 +1 @@ +/Users/ambv/Dropbox (Personal)/Python/black/docs/_build/generated/installation_and_usage.md \ No newline at end of file diff --git a/docs/license.md b/docs/license.md new file mode 120000 index 0000000..cf360a1 --- /dev/null +++ b/docs/license.md @@ -0,0 +1 @@ +/Users/ambv/Dropbox (Personal)/Python/black/docs/_build/generated/license.md \ No newline at end of file diff --git a/docs/requirements-docs.txt b/docs/requirements-docs.txt deleted file mode 100644 index 5e5376b..0000000 --- a/docs/requirements-docs.txt +++ /dev/null @@ -1,2 +0,0 @@ -sphinx>=1.7 -recommonmark==0.4.0 \ No newline at end of file diff --git a/docs/show_your_style.md b/docs/show_your_style.md new file mode 120000 index 0000000..15ad1c1 --- /dev/null +++ b/docs/show_your_style.md @@ -0,0 +1 @@ +/Users/ambv/Dropbox (Personal)/Python/black/docs/_build/generated/show_your_style.md \ No newline at end of file diff --git a/docs/technical_philosophy.md b/docs/technical_philosophy.md deleted file mode 100644 index 1052f0c..0000000 --- a/docs/technical_philosophy.md +++ /dev/null @@ -1,167 +0,0 @@ -# Technical Overview - -## The philosophy behind *Black* - -*Black* reformats entire files in place. It is not configurable. It -doesn't take previous formatting into account. It doesn't reformat -blocks that start with `# fmt: off` and end with `# fmt: on`. It also -recognizes [YAPF](https://github.com/google/yapf)'s block comments to -the same effect, as a courtesy for straddling code. - -## How *Black* formats files - -*Black* ignores previous formatting and applies uniform horizontal -and vertical whitespace to your code. The rules for horizontal -whitespace are pretty obvious and can be summarized as: do whatever -makes `pycodestyle` happy. - -As for vertical whitespace, *Black* tries to render one full expression -or simple statement per line. If this fits the allotted line length, -great. - -```py3 -# in: - -l = [1, - 2, - 3, -] - -# out: - -l = [1, 2, 3] -``` - -If not, *Black* will look at the contents of the first outer matching -brackets and put that in a separate indented line. - -```py3 -# in: - -l = [[n for n in list_bosses()], [n for n in list_employees()]] - -# out: - -l = [ - [n for n in list_bosses()], [n for n in list_employees()] -] -``` - -If that still doesn't fit the bill, it will decompose the internal -expression further using the same rule, indenting matching brackets -every time. If the contents of the matching brackets pair are -comma-separated (like an argument list, or a dict literal, and so on) -then *Black* will first try to keep them on the same line with the -matching brackets. If that doesn't work, it will put all of them in -separate lines. - -```py3 -# in: - -def very_important_function(template: str, *variables, file: os.PathLike, debug: bool = False): - """Applies `variables` to the `template` and writes to `file`.""" - with open(file, 'w') as f: - ... - -# out: - -def very_important_function( - template: str, - *variables, - file: os.PathLike, - debug: bool = False, -): - """Applies `variables` to the `template` and writes to `file`.""" - with open(file, 'w') as f: - ... -``` - -You might have noticed that closing brackets are always dedented and -that a trailing comma is always added. Such formatting produces smaller -diffs; when you add or remove an element, it's always just one line. -Also, having the closing bracket dedented provides a clear delimiter -between two distinct sections of the code that otherwise share the same -indentation level (like the arguments list and the docstring in the -example above). - -Unnecessary trailing commas are removed if an expression fits in one -line. This makes it 1% more likely that your line won't exceed the -allotted line length limit. - -*Black* avoids spurious vertical whitespace. This is in the spirit of -PEP 8 which says that in-function vertical whitespace should only be -used sparingly. One exception is control flow statements: *Black* will -always emit an extra empty line after ``return``, ``raise``, ``break``, -``continue``, and ``yield``. This is to make changes in control flow -more prominent to readers of your code. - -That's it. The rest of the whitespace formatting rules follow PEP 8 and -are designed to keep `pycodestyle` quiet. - -## Line length - -You probably noticed the peculiar default line length. *Black* defaults -to 88 characters per line, which happens to be 10% over 80. This number -was found to produce significantly shorter files than sticking with 80 -(the most popular), or even 79 (used by the standard library). In -general, [90-ish seems like the wise choice](https://youtu.be/wf-BqAjZb8M?t=260). - -If you're paid by the line of code you write, you can pass -`--line-length` with a lower number. *Black* will try to respect that. -However, sometimes it won't be able to without breaking other rules. In -those rare cases, auto-formatted code will exceed your allotted limit. - -You can also increase it, but remember that people with sight disabilities -find it harder to work with line lengths exceeding 100 characters. -It also adversely affects side-by-side diff review on typical screen -resolutions. Long lines also make it harder to present code neatly -in documentation or talk slides. - -If you're using Flake8, you can bump `max-line-length` to 88 and forget -about it. Alternatively, use [Bugbear](https://github.com/PyCQA/flake8-bugbear)'s -B950 warning instead of E501 and keep the max line length at 80 which -you are probably already using. You'd do it like this: - -```ini -[flake8] -max-line-length = 80 -... -select = C,E,F,W,B,B950 -ignore = E501 -``` - -You'll find *Black*'s own .flake8 config file is configured like this. -If you're curious about the reasoning behind B950, Bugbear's documentation -explains it. The tl;dr is "it's like highway speed limits, we won't -bother you if you overdo it by a few km/h". - -## Empty lines - -*Black* will allow single empty lines left by the original editors, -except when they're added within parenthesized expressions. Since such -expressions are always reformatted to fit minimal space, this whitespace -is lost. - -It will also insert proper spacing before and after function definitions. -It's one line before and after inner functions and two lines before and -after module-level functions. *Black* will put those empty lines also -between the function definition and any standalone comments that -immediately precede the given function. If you want to comment on the -entire function, use a docstring or put a leading comment in the function -body. - -## Editor integration - -* Visual Studio Code: [joslarson.black-vscode](https://marketplace.visualstudio.com/items?itemName=joslarson.black-vscode) - -Any tool that can pipe code through *Black* using its stdio mode (just -[use `-` as the file name](http://www.tldp.org/LDP/abs/html/special-chars.html#DASHREF2)). -The formatted code will be returned on stdout (unless `--check` was -passed). *Black* will still emit messages on stderr but that shouldn't -affect your use case. - -There is currently no integration with any other text editors. Vim and -Atom/Nuclide integration is planned by the author, others will require -external contributions. - -Patches welcome! ✨ 🍰 ✨ diff --git a/docs/testimonials.md b/docs/testimonials.md new file mode 120000 index 0000000..03fc5ae --- /dev/null +++ b/docs/testimonials.md @@ -0,0 +1 @@ +/Users/ambv/Dropbox (Personal)/Python/black/docs/_build/generated/testimonials.md \ No newline at end of file diff --git a/docs/the_black_code_style.md b/docs/the_black_code_style.md new file mode 120000 index 0000000..29b288b --- /dev/null +++ b/docs/the_black_code_style.md @@ -0,0 +1 @@ +/Users/ambv/Dropbox (Personal)/Python/black/docs/_build/generated/the_black_code_style.md \ No newline at end of file diff --git a/docs/usage.md b/docs/usage.md deleted file mode 100644 index 69ce846..0000000 --- a/docs/usage.md +++ /dev/null @@ -1,64 +0,0 @@ -# Installation and Usage - -## Installation - -*Black* can be installed by running `pip install black`. It requires -Python 3.6.0+ to run but you can reformat Python 2 code with it, too. - - -## Usage - -To get started right away with sensible defaults: - -``` -black {source_file_or_directory} -``` - - -### Command line options - -Black doesn't provide many options. You can list them by running -`black --help`: - -```text -Usage: black [OPTIONS] [SRC]... - - The uncompromising code formatter. - -Options: - -l, --line-length INTEGER How many character per line to allow. - [default: 88] - --check Don't write back the files, 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. - --fast / --safe If --fast given, skip temporary sanity checks. - [default: --safe] - --version Show the version and exit. - --help Show this message and exit. -``` - -`Black` is a well-behaved Unix-style command-line tool: - -* it does nothing if no sources are passed to it; -* it will read from standard input and write to standard output if `-` - is used as the filename; -* it only outputs messages to users on standard error; -* exits with code 0 unless an internal error occured (or `--check` was - used). - - -## NOTE: This tool is alpha quality at the moment - -*Black* can already successfully format itself and the standard library. -It also sports a decent test suite. However, it is still very new. -Things will probably be wonky for a while. This is made explicit by the -"Alpha" trove classifier, as well as by the "a" in the version number. -What this means for you is that **until the formatter becomes stable, -you should expect some formatting to change in the future**. - -Also, as a temporary safety measure, *Black* will check that the -reformatted code still produces a valid AST that is equivalent to the -original. This slows it down. If you're feeling confident, use -``--fast``. -- 2.39.5