pysassc - Man Page

Name

pysassc — libsass Documentation

This package provides a simple Python extension module sass which is binding LibSass (written in C/C++ by Hampton Catlin and Aaron Leung). It's very straightforward and there isn't any headache related Python distribution/deployment.  That means you can add just libsass into your setup.py's install_requires list or requirements.txt file.

It currently supports CPython 2.6, 2.7, 3.5--3.7, and PyPy 2.3+!

Features

Install

It's available on PyPI, so you can install it using pip:

$ pip install libsass
NOTE:

libsass requires some features introduced by the recent C++ standard. You need a C++ compiler that support those features. See also libsass project's README file.

Examples

Compile a String of Sass to CSS

>>> import sass
>>> sass.compile(string='a { b { color: blue; } }')
'a b {\n  color: blue; }\n'

Compile a Directory of Sass Files to CSS

>>> import sass
>>> import os
>>> os.mkdir('css')
>>> os.mkdir('sass')
>>> scss = """\
... $theme_color: #cc0000;
... body {
...     background-color: $theme_color;
... }
... """
>>> with open('sass/example.scss', 'w') as example_scss:
...      example_scss.write(scss)
...
>>> sass.compile(dirname=('sass', 'css'), output_style='compressed')
>>> with open('css/example.css') as example_css:
...     print(example_css.read())
...
body{background-color:#c00}

User's Guide

Using with Flask

This guide explains how to use libsass with the Flask web framework. sassutils package provides several tools that can be integrated into web applications written in Flask.

Contents

  • Using with Flask

    • Directory layout
    • Defining manifest
    • Building Sass/SCSS for each request
    • Building Sass/SCSS for each deployment

Directory layout

Imagine the project contained in such directory layout:

  • setup.py
  • myapp/

    • __init__.py
    • static/

      • sass/
      • css/
    • templates/

Sass/SCSS files will go inside myapp/static/sass/ directory. Compiled CSS files will go inside myapp/static/css/ directory. CSS files can be regenerated, so add myapp/static/css/ into your ignore list like .gitignore or .hgignore.

Defining manifest

The sassutils defines a concept named manifest. Manifest is the build settings of Sass/SCSS.  It specifies some paths related to building Sass/SCSS:

  • The path of the directory which contains Sass/SCSS source files.
  • The path of the directory which the compiled CSS files will go.
  • The path, exposed to HTTP (through WSGI), of the directory that will contain the compiled CSS files.

Every package may have its own manifest.  Paths have to be relative to the path of the package.

For example, in the above project, the package name is myapp. The path of the package is myapp/.  The path of the Sass/SCSS directory is static/sass/ (relative to the package directory). The path of the CSS directory is static/css/. The exposed path is /static/css.

These settings can be represented as the following manifests:

{
    'myapp': ('static/sass', 'static/css', '/static/css')
}

As you can see the above, the set of manifests are represented in dictionary, in which the keys are packages names and the values are tuples of paths.

Building Sass/SCSS for each request

SEE ALSO:

Flask --- Hooking in WSGI Middlewares

The section which explains how to integrate WSGI middlewares to Flask.

Flask --- flask:app-dispatch

The documentation which explains how Flask dispatches each request internally.

In development, manually building Sass/SCSS files for each change is a tedious task.  SassMiddleware makes the web application build Sass/SCSS files for each request automatically. It's a WSGI middleware, so it can be plugged into the web app written in Flask.

SassMiddleware takes two required parameters:

  • The WSGI-compliant callable object.
  • The set of manifests represented as a dictionary.

So:

from flask import Flask
from sassutils.wsgi import SassMiddleware

app = Flask(__name__)

app.wsgi_app = SassMiddleware(app.wsgi_app, {
    'myapp': ('static/sass', 'static/css', '/static/css')
})

And then, if you want to link a compiled CSS file, use the url_for() function:

<link href="{{ url_for('static', filename='css/style.scss.css') }}"
      rel="stylesheet" type="text/css">
NOTE:

The linked filename is style.scss.css, not just style.scss. All compiled filenames have trailing .css suffix.

Building Sass/SCSS for each deployment

NOTE:

This section assumes that you use setuptools for deployment.

SEE ALSO:

Flask --- flask:distribute-deployment

How to deploy Flask application using setuptools.

If libsass is installed in the site-packages (for example, your virtualenv), the setup.py script also gets a new command provided by libsass: build_sass. The command is aware of the sass_manifests option of setup.py and builds all Sass/SCSS sources according to the manifests.

Add these arguments to setup.py script:

setup(
    # ...,
    setup_requires=['libsass >= 0.6.0'],
    sass_manifests={
        'myapp': ('static/sass', 'static/css', '/static/css')
    }
)

The setup_requires option makes sure that libsass is installed in site-packages (for example, your virtualenv) before the setup.py script.  That means if you run the setup.py script and libsass isn't installed in advance, it will automatically install libsass first.

The sass_manifests specifies the manifests for libsass.

Now setup.py build_sass will compile all Sass/SCSS files in the specified path and generates compiled CSS files inside the specified path (according to the manifests).

If you use it with sdist or bdist commands, the packed archive will also contain the compiled CSS files!

$ python setup.py build_sass sdist

You can add aliases to make these commands always run the build_sass command first.  Make setup.cfg config:

[aliases]
sdist = build_sass sdist
bdist = build_sass bdist

Now it automatically builds Sass/SCSS sources and include the compiled CSS files to the package archive when you run setup.py sdist.

Changelog

Version 0.20.0

Released on November 3, 2019.

  • Produce abi3 wheels on macos / linux [#307 by Anthony Sottile]
  • Follow up the libsass upstream: 3.6.4 --- See the release notes of LibSass 3.6.4. [#313 by Anthony Sottile]

Version 0.19.4

Released on November 3, 2019.

  • Follow up the libsass upstream: 3.6.3 --- See the release notes of LibSass 3.6.3. [#304 by Anthony Sottile]

Version 0.19.3

Released on October 5, 2019.

  • Follow up the libsass upstream: 3.6.2 --- See the release notes of LibSass 3.6.2. [#302 by Anthony Sottile]

Version 0.19.2

Released on June 16, 2019.

  • Follow up the libsass upstream: 3.6.1 --- See the release notes of LibSass 3.6.1. [#298 by Anthony Sottile]

Version 0.19.1

Released on May 18, 2019.

  • Re-release of 0.19.0 with windows python2.7 wheels [#297 by Anthony Sottile]

Version 0.19.0

Released on May 18, 2019.

  • Follow up the libsass upstream: 3.6.0 --- See the release notes of LibSass 3.6.0. [#295 by Anthony Sottile]

Version 0.18.0

Release on March 13, 2019

  • Add support for previous import path to importer callbacks [#287 #291 by Frankie Dintino]

Version 0.17.0

Release on January 03, 2019

Version 0.16.1

Released on November 25, 2018.

  • Fix compilation on macos mojave [#276 #277 by Anthony Sottile]
  • Fix .sass in WsgiMiddleware for strip_extension=True [#278 by Anthony Sottile]

Version 0.16.0

Released on November 13, 2018.

  • Use -lc++ link flag when compiling with clang [#270 by Christian Thieme #271 by Anthony Sottile]
  • Honor strip_extension in SassMiddleware [#274 by Anthony Sottile]
  • Follow up the libsass upstream: 3.5.5 --- See the release notes of LibSass 3.5.5. [#275 by Anthony Sottile]

Version 0.15.1

Released on September 24, 2018.

  • Fix setup.py sdist (regressed in 0.15.0) [#267 by Anthony Sottile]

Version 0.15.0

Released on September 16, 2018.

  • Fix invalid escape sequences [#249 by Anthony Sottile]
  • Add code of conduct [#251 by Nick Schonning]
  • Add support for python3.7 and remove testing for python3.4 [#254 by Anthony Sottile]
  • Add strip_extension option for wsgi / distutils builder [#55 #258 by Anthony Sottile #260 by Morten Brekkevold]
  • Deprecate sassc (replaced by pysassc).  [#262 by Anthony Sottile]
  • Import abc classes from collections.abc to remove DeprecationWarning [#264 by Gary van der Merwe #265 by Anthony Sottile]

Version 0.14.5

Released on April 25, 2018.

  • Follow up the libsass upstream: 3.5.4 --- See the release notes of LibSass 3.5.4. [#247 by Anthony Sottile]

Version 0.14.4

Released on April 24, 2018.

  • Add ability to specify imports for custom extensions.  This provides a way to enable imports of .css files (which was removed in 3.5.3). Specify --import-extensions .css to restore the previous behavior. [#246 by Samuel Colvin]

Version 0.14.3

Released on April 23, 2018.

  • Follow up the libsass upstream: 3.5.3 --- See the release notes of LibSass 3.5.3. [#244 by Anthony Sottile]

Version 0.14.2

Released on March 16, 2018.

  • Follow up the libsass upstream: 3.5.2 --- See the release notes of LibSass 3.5.2. [#243 by Anthony Sottile]

Version 0.14.1

Released on March 12, 2018.

  • Follow up the libsass upstream: 3.5.1 --- See the release notes of LibSass 3.5.1. [#242 by Anthony Sottile]

Version 0.14.0

Released on March 6, 2018.

  • Follow up the libsass upstream: 3.5.0 --- See the release notes of LibSass 3.5.0. [#241 by Anthony Sottile]
  • SassList type gained an additional option bracketed=False to match the upstream changes to the sass_list type. [#184 by Anthony Sottile]

Version 0.13.7

Released on February 5, 2018.

  • Follow up the libsass upstream: 3.4.9 --- See the release notes of LibSass 3.4.9. [#232 by Anthony Sottile]

Version 0.13.6

Released on January 19, 2018.

  • libsass-python has moved to the sass organization!

Version 0.13.5

Released on January 11, 2018.

  • Follow up the libsass upstream: 3.4.8 --- See the release notes of LibSass 3.4.8. [#228 by Anthony Sottile]

Version 0.13.4

Released on November 14, 2017.

  • Follow up the libsass upstream: 3.4.7 --- See the release notes of LibSass 3.4.7. [#226 by Anthony Sottile]

Version 0.13.3

Released on October 11, 2017.

  • Sort input files for determinism [#212 by Bernhard M. Wiedemann]
  • Include LICENSE file in distributions [#216 by Dougal J. Sutherland]
  • Add a pysassc entry to replace sassc [#218 by Anthony Sottile]
  • Enable building with dynamic linking [#219 by Marcel Plch]
  • Follow up the libsass upstream: 3.4.6 --- See the release notes of LibSass 3.4.6. [#221 by Anthony Sottile]

Version 0.13.2

Released on June 14, 2017.

  • Always add cwd to import paths [#208 by Anthony Sottile]

Version 0.13.1

Released on June 8, 2017.

  • Follow up the libsass upstream: 3.4.5 --- See the release notes of LibSass 3.4.5. [#207 by Anthony Sottile]

Version 0.13.0

Released on June 7, 2017.

  • Use getfullargspec when available in python 3. [#188 by Thom Wiggers]
  • Use sass_copy_c_string instead of strdup for portability [#196 by Anthony Sottile]
  • Use -std=gnu++0x to fix installation under cygwin [#195 #197 by Anthony Sottile]
  • Correct source map url [#201 #202 by Anthony Sottile]
  • Remove --watch [#203 by Anthony Sottile]
  • Follow up the libsass upstream: 3.4.4 --- See the release notes of LibSass 3.4.4. [#205 by Anthony Sottile]

Version 0.12.3

Released on January 7, 2017.

  • Follow up the libsass upstream: 3.4.3 --- See the release notes of LibSass 3.4.3. [#178 by Anthony Sottile]

Version 0.12.2

Released on January 5, 2017.

  • Follow up the libsass upstream: 3.4.2 --- See the release notes of LibSass 3.4.2. [#176 by Anthony Sottile]

Version 0.12.1

Released on December 20, 2016.

  • Follow up the libsass upstream: 3.4.1 --- See the release notes of LibSass 3.4.1. [#175 by Anthony Sottile]

Version 0.12.0

Released on December 10, 2016.

  • Follow up the libsass upstream: 3.4.0 --- See the release notes of LibSass 3.4.0. [#173 by Anthony Sottile]

Version 0.11.2

Released on October 24, 2016.

  • Drop support for python2.6 [#158 by Anthony Sottile]
  • Deprecate --watch [#156 by Anthony Sottile]
  • Preserve line endings [#160 by Anthony Sottile]
  • Follow up the libsass upstream: 3.3.6 --- See the release notes of LibSass 3.3.6. [#167 by Anthony Sottile]

Version 0.11.1

Released on April 22, 2016.

  • Follow up the libsass upstream: 3.3.5 --- See the release notes of LibSass 3.3.5. [#148 by Anthony Sottile]

Version 0.11.0

Released on March 23, 2016.

  • Follow up the libsass upstream: 3.3.4 --- See the release notes of LibSass 3.3.4. [#144 by Anthony Sottile]
  • Expose libsass version in sassc --version and sass.libsass_version [#142 #141 #140 by Anthony Sottile]
  • Fix warning about unused enum on switch [#127 #131 by Anthony Sottile]
  • Sourcemaps no longer imply source comments [#124 #130 by Tim Tisdall]
  • Add --source-comments option to sassc [#124 #130 by Anthony Sottile]
  • Improve formatting of CompileError under python3 [#123 by Anthony Sottile]
  • Raise when compiling a directory which does not exist [#116 #119 by Anthony Sottile]

Version 0.10.1

Released on January 29, 2016.

  • Follow up the libsass upstream: 3.3.3 --- See the release notes of LibSass 3.3.3. [by Anthony Sottile]
  • Allow -t for style like sassc [#98 by Anthony Sottile]

Version 0.10.0

Released on December 15, 2015.

  • Support custom import callbacks [#81 by Alice Zoë Bevan–McGregor, Anthony Sottile]
  • Disallow arbitrary kwargs in compile() [#109 by Anthony Sottile]

Version 0.9.3

Released on December 03, 2015.

  • Support "indented" Sass compilation [#41 by Alice Zoë Bevan–McGregor]
  • Fix wheels on windows [#28 #49 by Anthony Sottile]

Version 0.9.2

Released on November 12, 2015.

  • Follow up the libsass upstream: 3.3.2 --- See the release notes of LibSass 3.3.2. [by Anthony Sottile]
  • Require VS 2015 to build on windows [#99 by Anthony Sottile]

Version 0.9.1

Released on October 29, 2015.

  • Follow up the libsass upstream: 3.3.1 --- See the release notes of LibSass 3.3.1. [by Anthony Sottile]

Version 0.9.0

Released on October 28, 2015.

  • Fix a bug with writing UTF-8 to a file [#72 by Caleb Ely]
  • Fix a segmentation fault on ^C [#87 by Anthony Sottile]
  • Follow up the libsass upstream: 3.3.0 --- See the release notes of LibSass 3.3.0. [#96 by Anthony Sottile]

Version 0.8.3

Released on August 2, 2015.

  • Follow up the libsass upstream: 3.2.5 --- See the release notes of LibSass 3.2.5.  [#79, #80 by Anthony Sottile]
  • Fixed a bug that *.sass files were ignored. [#78 by Guilhem MAS-PAITRAULT]

Version 0.8.2

Released on May 19, 2015.

  • Follow up the libsass upstream: 3.2.4 --- See the release notes of LibSass 3.2.3, and 3.2.4.  [#69 by Anthony Sottile]
  • The default value of SassMiddleware's error_status parameter was changed from '500 Internal Server Error' to '200 OK' so that Mozilla Firefox can render the error message well. [#67, #68, #70 by zxv]

Version 0.8.1

Released on May 14, 2015.

  • Fixed a bug that there was no 'expanded' in sass.OUTPUT_STYLES but 'expected' instead which is a typo.  [#66 by Triangle717]
  • Fixed broken FreeBSD build.  [#65 by Toshiharu Moriyama]

Version 0.8.0

Released on May 3, 2015.

  • Follow up the libsass upstream: 3.2.2 --- See the release notes of LibSass 3.2.0, 3.2.1, and 3.2.2. [#61, #52, #56, #58, #62, #64 by Anthony Sottile]

    • Compact and expanded output styles  [#37]
    • Strings and interpolation closer to Ruby Sass
    • The correctness of the generated sourcemap files
    • Directive buddling
    • Full support for the @at-root directive
    • Full support for !global variable scoping
  • Now underscored files are ignored when compiling a directory. [#57 by Anthony Sottile]
  • Fixed broken FreeBSD build.  [#34, #60 by Ilya Baryshev]
  • SassMiddleware became to log syntax errors if exist during compilation to sassutils.wsgi.SassMiddleware logger with level ERROR.  [#42]

Version 0.7.0

Released on March 6, 2015.

Anthony Sottile contributed to the most of this release.  Huge thanks to him!

  • Follow up the libsass upstream: 3.1.0 --- See the release note of LibSass. [#38, #43 by Anthony Sottile]

    • Custom functions and imports
    • Decrementing in @for loops
    • @debug and @error
    • not operator
    • nth() for maps
    • inspect()
    • feature-exists()
    • unique-id()
    • random()
  • Added custom functions support.  [#13, #44 by Anthony Sottile]

    • Added sass.SassFunction class.
    • Added custom_functions parameter to sass.compile() function.
    • Added data types for custom functions:

      • sass.SassNumber
      • sass.SassColor
      • sass.SassList
      • sass.SassMap
      • sass.SassError
      • sass.SassWarning
  • Added precision parameter to sass.compile() function. [#39 by Andrea Stagi]
  • sassc has a new -p/--precision option.  [#39 by Andrea Stagi]

Version 0.6.2

Released on November 25, 2014.

Although 0.6.0--0.6.1 have needed GCC (G++) 4.8+, LLVM Clang 3.3+, now it became back to only need GCC (G++) 4.6+, LLVM Clang 2.9+, or Visual Studio 2013 Update 4+.

  • Follow up the libsass upstream: 3.0.2 --- See the release note of libsass. [#33 by Rodolphe Pelloux-Prayer]
  • Fixed a bug that sassc --watch crashed when a file is not compilable on the first try.  [#32 by Alan Justino da Silva]
  • Fixed broken build on Windows.

Version 0.6.1

Released on November 6, 2014.

  • Follow up the libsass upstream: 3.0.1 --- See the release note of LibSass.
  • Fixed a bug that SassMiddleware never closes the socket on some WSGI servers e.g. eventlet.wsgi.

Version 0.6.0

Released on October 27, 2014.

Note that since libsass-python 0.6.0 (and libsass 3.0) it requires C++11 to compile.  Although 0.6.2 became back to only need GCC (G++) 4.6+, LLVM Clang 2.9+, from 0.6.0 to 0.6.1 you need GCC (G++) 4.8+, LLVM Clang 3.3+, or Visual Studio 2013 Update 4+.

  • Follow up the libsass upstream: 3.0 --- See the release note of LibSass.

    • Decent extends support
    • Basic Sass Maps Support
    • Better UTF-8 Support
    • call() function
    • Better Windows Support
    • Spec Enhancements
  • Added missing partial import support.  [#27 by item4]
  • SOURCE_COMMENTS became deprecated.
  • sass.compile()'s parameter source_comments now can take only bool instead of str.  String values like 'none', 'line_numbers', and 'map' become deprecated, and will be obsolete soon.
  • build_directory() function has a new optional parameter output_style.
  • build() method has a new optional parameter output_style.
  • Added --output-style/-s option to build_sass command.  [#25]

Version 0.5.1

Released on September 23, 2014.

  • Fixed a bug that SassMiddleware yielded str instead of bytes on Python 3.
  • Fixed several Unicode-related bugs on Windows.
  • Fixed a bug that build_directory(), SassMiddleware, and build_sass don't recursively build subdirectories.

Version 0.5.0

Released on June 6, 2014.

  • Follow up the libsass upstream: 2.0 --- See the release note of LibSass.

    • Added indented syntax support (*.sass files).
    • Added expanded selector support (BEM).
    • Added string functions.
    • Fixed UTF-8 support.
    • Backward incompatibility: broken extends.

Unstable version 0.4.2.20140529.cd3ee1cbe3

Released on May 29, 2014.

  • Version scheme changed to use periods (.) instead of hyphens (-) due to setuptools seems to treat hyphens special.
  • Fixed malformed packaging that doesn't correctly preserve the package name and version.

Unstable Version 0.4.2-20140528-cd3ee1cbe3

Released on May 28, 2014.

  • Follow up the libsass upstream: cd3ee1cbe34d5316eb762a43127a3de9575454ee.

Version 0.4.2

Released on May 22, 2014.

  • Fixed build failing on Mac OS X 10.8 or earlier.  [#19]
  • Fixed UnicodeEncodeError that Manifest.build_one() method rises when the input source contains any non-ASCII Unicode characters.

Version 0.4.1

Released on May 20, 2014.

  • Fixed UnicodeEncodeError that rise when the input source contains any non-ASCII Unicode characters.

Version 0.4.0

Released on May 6, 2014.

  • sassc has a new -w/--watch option.
  • Expose source maps support:

    • sassc has a new -m/-g/--sourcemap option.
    • SassMiddleware now also creates source map files with filenames followed by .map suffix.
    • Manifest.build_one() method has a new source_map option.  This option builds also a source map file with the filename followed by .map suffix.
    • sass.compile() has a new optional parameter source_comments. It can be one of sass.SOURCE_COMMENTS keys.  It also has a new parameter source_map_filename which is required only when source_comments='map'.
  • Fixed Python 3 incompatibility of sassc program.
  • Fixed a bug that multiple include_paths doesn't work on Windows.

Version 0.3.0

Released on February 21, 2014.

  • Added support for Python 3.3.  [#7]
  • Dropped support for Python 2.5.
  • Fixed build failing on Mac OS X. [#4, #5, #6 by Hyungoo Kang]
  • Now builder creates target recursive subdirectories even if it doesn't exist yet, rather than siliently fails. [#8, #9 by Philipp Volguine]
  • Merged recent changes from libsass 1.0.1: 57a2f62--v1.0.1.

    • Supports variable arguments.
    • Supports sourcemaps.

Version 0.2.4

Released on December 4, 2012.

  • Added sassc CLI executable script.
  • Added sass.OUTPUT_STYLES constant map.
  • Merged recent changes from libsass upstream: e997102--a84b181.

Version 0.2.3

Released on October 24, 2012.

  • sassutils.distutils: Prevent double monkey patch of sdist.
  • Merged upstream changes of libsass.

Version 0.2.2

Released on September 28, 2012.

  • Fixed a link error on PyPy and Linux.
  • Fixed build errors on Windows.

Version 0.2.1

Released on September 12, 2012.

  • Support Windows.

Version 0.2.0

Released on August 24, 2012.

  • Added new sassutils package.

    • Added sassutils.builder module to build the whole directory at a time.
    • Added sassutils.distutils module for distutils and setuptools integration.
    • Added sassutils.wsgi module which provides a development-purpose WSGI middleware.
  • Added build_sass command for distutils/setuptools.

Version 0.1.1

Released on August 18, 2012.

  • Fixed segmentation fault for reading filename which does not exist. Now it raises a proper exceptions.IOError exception.

Version 0.1.0

Released on August 17, 2012.  Initial version.

References

pysassc --- SassC compliant command line interface

This provides SassC compliant CLI executable named pysassc:

$ pysassc
Usage: pysassc [options] SCSS_FILE [CSS_FILE]

There are options as well:

-t <style>, --style <style>

Coding style of the compiled result.  The same as sass.compile() function's output_style keyword argument.  Default is nested.

-s <style>, --output-style <style>

Alias for -t / --style.

Deprecated since version 0.11.0.

-I <dir>, --include-path <dir>

Optional directory path to find @imported (S)CSS files. Can be multiply used.

-m,  -g,  --sourcemap

Emit source map.  Requires the second argument (output CSS filename). The filename of source map will be the output CSS filename followed by .map.

New in version 0.4.0.

-p,  --precision

Set the precision for numbers. Default is 5.

New in version 0.7.0.

--source-comments

Include debug info in output.

New in version 0.11.0.

--sourcemap-file

Output file for source map

New in version 0.17.0.

--sourcemap-contents

Embed sourcesContent in source map.

New in version 0.17.0.

--sourcemap-embed

Embed sourceMappingUrl as data URI

New in version 0.17.0.

--omit-sourcemap-url

Omit source map URL comment from output

New in version 0.17.0.

--sourcemap-root

Base path, will be emitted to sourceRoot in source-map as is

New in version 0.17.0.

-v,  --version

Prints the program version.

-h,  --help

Prints the help message.

sass --- Binding of libsass

This simple C extension module provides a very simple binding of libsass, which is written in C/C++.  It contains only one function and one exception type.

>>> import sass
>>> sass.compile(string='a { b { color: blue; } }')
'a b {
  color: blue; }
'
exception sass.CompileError(msg)

The exception type that is raised by compile(). It is a subtype of exceptions.ValueError.

sass.MODES = frozenset({'dirname', 'filename', 'string'})

(frozenset) The set of keywords compile() can take.

sass.OUTPUT_STYLES = {'compact': 2, 'compressed': 3, 'expanded': 1, 'nested': 0}

(collections.abc.Mapping) The dictionary of output styles. Keys are output name strings, and values are flag integers.

sass.SOURCE_COMMENTS = {'default': 1, 'line_numbers': 1, 'map': 2, 'none': 0}

(collections.abc.Mapping) The dictionary of source comments styles. Keys are mode names, and values are corresponding flag integers.

New in version 0.4.0.

Deprecated since version 0.6.0.

class sass.SassColor(r, g, b, a)

class sass.SassError(msg)

class sass.SassFunction(name, arguments, callable_)

Custom function for Sass.  It can be instantiated using from_lambda() and from_named_function() as well.

Parameters
  • name (str) -- the function name
  • arguments (collections.abc.Sequence) -- the argument names
  • callable (collections.abc.Callable) -- the actual function to be called

New in version 0.7.0.

classmethod from_lambda(name, lambda_)

Make a SassFunction object from the given lambda_ function.  Since lambda functions don't have their name, it need its name as well.  Arguments are automatically inspected.

Parameters
  • name (str) -- the function name
  • lambda (types.LambdaType) -- the actual lambda function to be called
Returns

a custom function wrapper of the lambda_ function

Return type

SassFunction

classmethod from_named_function(function)

Make a SassFunction object from the named function. Function name and arguments are automatically inspected.

Parameters

function (types.FunctionType) -- the named function to be called

Returns

a custom function wrapper of the function

Return type

SassFunction

property signature

Signature string of the function.

class sass.SassList(items, separator, bracketed=False)

class sass.SassMap(*args, **kwargs)

Because sass maps can have mapping types as keys, we need an immutable hashable mapping type.

New in version 0.7.0.

class sass.SassNumber(value, unit)

class sass.SassWarning(msg)

sass.and_join(strings)

Join the given strings by commas with last ' and ' conjuction.

>>> and_join(['Korea', 'Japan', 'China', 'Taiwan'])
'Korea, Japan, China, and Taiwan'
Parameters

strings -- a list of words to join

Returns

a joined string

Return type

str, basestring

sass.compile(**kwargs)

There are three modes of parameters compile() can take: string, filename, and dirname.

The string parameter is the most basic way to compile Sass. It simply takes a string of Sass code, and then returns a compiled CSS string.

Parameters
  • string (str) -- Sass source code to compile.  it's exclusive to filename and dirname parameters
  • output_style (str) -- an optional coding style of the compiled result. choose one of: 'nested' (default), 'expanded', 'compact', 'compressed'
  • source_comments (bool) -- whether to add comments about source lines. False by default
  • source_map_contents (bool) -- embed include contents in map
  • source_map_embed (bool) -- embed sourceMappingUrl as data URI
  • omit_source_map_url (bool) -- omit source map URL comment from output
  • source_map_root (str) -- base path, will be emitted in source map as is
  • include_paths (collections.abc.Sequence) -- an optional list of paths to find @imported Sass/CSS source files
  • precision (int) -- optional precision for numbers. 5 by default.
  • custom_functions (set, collections.abc.Sequence, collections.abc.Mapping) -- optional mapping of custom functions. see also below custom functions description
  • custom_import_extensions -- (ignored, for backward compatibility)
  • indented (bool) -- optional declaration that the string is Sass, not SCSS formatted. False by default
  • importers (collections.abc.Callable) -- optional callback functions. see also below importer callbacks description
Returns

the compiled CSS string

Return type

str

Raises

sass.CompileError -- when it fails for any reason (for example the given Sass has broken syntax)

The filename is the most commonly used way.  It takes a string of Sass filename, and then returns a compiled CSS string.

Parameters
  • filename (str) -- the filename of Sass source code to compile. it's exclusive to string and dirname parameters
  • output_style (str) -- an optional coding style of the compiled result. choose one of: 'nested' (default), 'expanded', 'compact', 'compressed'
  • source_comments (bool) -- whether to add comments about source lines. False by default
  • source_map_filename (str) -- use source maps and indicate the source map output filename.  None means not using source maps.  None by default.
  • source_map_contents (bool) -- embed include contents in map
  • source_map_embed (bool) -- embed sourceMappingUrl as data URI
  • omit_source_map_url (bool) -- omit source map URL comment from output
  • source_map_root (str) -- base path, will be emitted in source map as is
  • include_paths (collections.abc.Sequence) -- an optional list of paths to find @imported Sass/CSS source files
  • precision (int) -- optional precision for numbers. 5 by default.
  • custom_functions (set, collections.abc.Sequence, collections.abc.Mapping) -- optional mapping of custom functions. see also below custom functions description
  • custom_import_extensions -- (ignored, for backward compatibility)
  • importers (collections.abc.Callable) -- optional callback functions. see also below importer callbacks description
Returns

the compiled CSS string, or a pair of the compiled CSS string and the source map string if source_map_filename is set

Return type

str, tuple

Raises
  • sass.CompileError -- when it fails for any reason (for example the given Sass has broken syntax)
  • exceptions.IOError -- when the filename doesn't exist or cannot be read

The dirname is useful for automation.  It takes a pair of paths. The first of the dirname pair refers the source directory, contains several Sass source files to compiled.  Sass source files can be nested in directories.  The second of the pair refers the output directory that compiled CSS files would be saved.  Directory tree structure of the source directory will be maintained in the output directory as well. If dirname parameter is used the function returns None.

Parameters
  • dirname (tuple) -- a pair of (source_dir, output_dir). it's exclusive to string and filename parameters
  • output_style (str) -- an optional coding style of the compiled result. choose one of: 'nested' (default), 'expanded', 'compact', 'compressed'
  • source_comments (bool) -- whether to add comments about source lines. False by default
  • source_map_contents (bool) -- embed include contents in map
  • source_map_embed (bool) -- embed sourceMappingUrl as data URI
  • omit_source_map_url (bool) -- omit source map URL comment from output
  • source_map_root (str) -- base path, will be emitted in source map as is
  • include_paths (collections.abc.Sequence) -- an optional list of paths to find @imported Sass/CSS source files
  • precision (int) -- optional precision for numbers. 5 by default.
  • custom_functions (set, collections.abc.Sequence, collections.abc.Mapping) -- optional mapping of custom functions. see also below custom functions description
  • custom_import_extensions -- (ignored, for backward compatibility)
Raises

sass.CompileError -- when it fails for any reason (for example the given Sass has broken syntax)

The custom_functions parameter can take three types of forms:

set/Sequence of SassFunctions

It is the most general form.  Although pretty verbose, it can take any kind of callables like type objects, unnamed functions, and user-defined callables.

sass.compile(
    ...,
    custom_functions={
        sass.SassFunction('func-name', ('$a', '$b'), some_callable),
        ...
    }
)
Mapping of names to functions

Less general, but easier-to-use form.  Although it's not it can take any kind of callables, it can take any kind of functions defined using def/lambda syntax. It cannot take callables other than them since inspecting arguments is not always available for every kind of callables.

sass.compile(
    ...,
    custom_functions={
        'func-name': lambda a, b: ...,
        ...
    }
)

set/Sequence of named functions

Not general, but the easiest-to-use form for named functions. It can take only named functions, defined using def. It cannot take lambdas sinc names are unavailable for them.

def func_name(a, b):
    return ...

sass.compile(
    ...,
    custom_functions={func_name}
)

Newer versions of libsass allow developers to define callbacks to be called and given a chance to process @import directives. You can define yours by passing in a list of callables via the importers parameter. The callables must be passed as 2-tuples in the form:

(priority_int, callback_fn)

A priority of zero is acceptable; priority determines the order callbacks are attempted.

These callbacks can accept one or two string arguments. The first argument is the path that was passed to the @import directive; the second (optional) argument is the previous resolved path, where the @import directive was found. The callbacks must either return None to indicate the path wasn't handled by that callback (to continue with others or fall back on internal libsass filesystem behaviour) or a list of one or more tuples, each in one of three forms:

  • A 1-tuple representing an alternate path to handle internally; or,
  • A 2-tuple representing an alternate path and the content that path represents; or,
  • A 3-tuple representing the same as the 2-tuple with the addition of a "sourcemap".

All tuple return values must be strings. As a not overly realistic example:

def my_importer(path, prev):
    return [(path, '#' + path + ' { color: red; }')]

sass.compile(
        ...,
        importers=[(0, my_importer)]
    )

Now, within the style source, attempting to @import 'button'; will instead attach color: red as a property of an element with the imported name.

New in version 0.4.0: Added source_comments and source_map_filename parameters.

Changed in version 0.6.0: The source_comments parameter becomes to take only bool instead of str.

Deprecated since version 0.6.0: Values like 'none', 'line_numbers', and 'map' for the source_comments parameter are deprecated.

New in version 0.7.0: Added precision parameter.

New in version 0.7.0: Added custom_functions parameter.

New in version 0.11.0: source_map_filename no longer implies source_comments.

New in version 0.17.0: Added source_map_contents, source_map_embed, omit_source_map_url, and source_map_root parameters.

New in version 0.18.0: The importer callbacks can now take a second argument, the previously- resolved path, so that importers can do relative path resolution.

sassutils.builder --- Build the whole directory

class sassutils.builder.Manifest(sass_path, css_path=None, wsgi_path=None, strip_extension=None)

Building manifest of Sass/SCSS.

Parameters
  • sass_path (str, basestring) -- the path of the directory that contains Sass/SCSS source files
  • css_path (str, basestring) -- the path of the directory to store compiled CSS files
  • strip_extension (bool) -- whether to remove the original file extension
build(package_dir, output_style='nested')

Builds the Sass/SCSS files in the specified sass_path. It finds sass_path and locates css_path as relative to the given package_dir.

Parameters
  • package_dir (str, basestring) -- the path of package directory
  • output_style (str) -- an optional coding style of the compiled result. choose one of: 'nested' (default), 'expanded', 'compact', 'compressed'
Returns

the set of compiled CSS filenames

Return type

frozenset

New in version 0.6.0: The output_style parameter.

build_one(package_dir, filename, source_map=False)

Builds one Sass/SCSS file.

Parameters
  • package_dir (str, basestring) -- the path of package directory
  • filename (str, basestring) -- the filename of Sass/SCSS source to compile
  • source_map (bool) -- whether to use source maps.  if True it also write a source map to a filename followed by .map suffix. default is False
Returns

the filename of compiled CSS

Return type

str, basestring

New in version 0.4.0: Added optional source_map parameter.

resolve_filename(package_dir, filename)

Gets a proper full relative path of Sass source and CSS source that will be generated, according to package_dir and filename.

Parameters
  • package_dir (str, basestring) -- the path of package directory
  • filename (str, basestring) -- the filename of Sass/SCSS source to compile
Returns

a pair of (sass, css) path

Return type

tuple

unresolve_filename(package_dir, filename)

Retrieves the probable source path from the output filename.  Pass in a .css path to get out a .scss path.

Parameters
  • package_dir (str) -- the path of the package directory
  • filename (str) -- the css filename
Returns

the scss filename

Return type

str

sassutils.builder.SUFFIXES = frozenset({'sass', 'scss'})

(frozenset) The set of supported filename suffixes.

sassutils.builder.SUFFIX_PATTERN = re.compile('[.](scss|sass)$')

(re.RegexObject) The regular expression pattern which matches to filenames of supported SUFFIXES.

sassutils.builder.build_directory(sass_path, css_path, output_style='nested', _root_sass=None, _root_css=None, strip_extension=False)

Compiles all Sass/SCSS files in path to CSS.

Parameters
  • sass_path (str, basestring) -- the path of the directory which contains source files to compile
  • css_path (str, basestring) -- the path of the directory compiled CSS files will go
  • output_style (str) -- an optional coding style of the compiled result. choose one of: 'nested' (default), 'expanded', 'compact', 'compressed'
Returns

a dictionary of source filenames to compiled CSS filenames

Return type

collections.abc.Mapping

New in version 0.6.0: The output_style parameter.

sassutils.distutils --- setuptools/distutils integration

This module provides extensions (and some magical monkey-patches, sorry) of the standard distutils and setuptools (now it's named Distribute) for libsass.

To use this, add libsass into setup_requires (not install_requires) option of the setup.py script:

from setuptools import setup

setup(
    # ...,
    setup_requires=['libsass >= 0.6.0']
)

It will adds build_sass command to the setup.py script:

$ python setup.py build_sass

This commands builds Sass/SCSS files to compiled CSS files of the project and makes the package archive (made by sdist, bdist, and so on) to include these compiled CSS files.

To set the directory of Sass/SCSS source files and the directory to store compiled CSS files, specify sass_manifests option:

from setuptools import find_packages, setup

setup(
    name='YourPackage',
    packages=find_packages(),
    sass_manifests={
        'your.webapp': ('static/sass', 'static/css')
    },
    setup_requires=['libsass >= 0.6.0']
)

The option should be a mapping of package names to pairs of paths, e.g.:

{
    'package': ('static/sass', 'static/css'),
    'package.name': ('static/scss', 'static')
}

The option can also be a mapping of package names to manifest dictionaries:

{
    'package': {
        'sass_path': 'static/sass',
        'css_path': 'static/css',
        'strip_extension': True,
    },
}

New in version 0.15.0: Added strip_extension so a.scss is compiled to a.css instead of a.scss.css.  This option will default to True in the future.

New in version 0.6.0: Added --output-style/-s option to build_sass command.

class sassutils.distutils.build_sass(dist, **kw)

Builds Sass/SCSS files to CSS files.

finalize_options()

Set final values for all the options that this command supports. This is always called as late as possible, ie.  after any option assignments from the command-line or from other commands have been done.  Thus, this is the place to code option dependencies: if 'foo' depends on 'bar', then it is safe to set 'foo' from 'bar' as long as 'foo' still has the same value it was assigned in 'initialize_options()'.

This method must be implemented by all command classes.

get_package_dir(package)

Returns the directory, relative to the top of the source distribution, where package package should be found (at least according to the package_dir option, if any).

Copied from distutils.command.build_py.get_package_dir() method.

initialize_options()

Set default values for all the options that this command supports.  Note that these defaults may be overridden by other commands, by the setup script, by config files, or by the command-line.  Thus, this is not the place to code dependencies between options; generally, 'initialize_options()' implementations are just a bunch of "self.foo = None" assignments.

This method must be implemented by all command classes.

run()

A command's raison d'etre: carry out the action it exists to perform, controlled by the options initialized in 'initialize_options()', customized by other commands, the setup script, the command-line, and config files, and finalized in 'finalize_options()'.  All terminal output and filesystem interaction should be done by 'run()'.

This method must be implemented by all command classes.

sassutils.distutils.validate_manifests(dist, attr, value)

Verifies that value is an expected mapping of package to sassutils.builder.Manifest.

sassutils.wsgi --- WSGI middleware for development purpose

class sassutils.wsgi.SassMiddleware(app, manifests, package_dir={}, error_status='200 OK')

WSGI middleware for development purpose.  Everytime a CSS file has requested it finds a matched Sass/SCSS source file and then compiled it into CSS.

It shows syntax errors in three ways:

Heading comment

The result CSS includes detailed error message in the heading CSS comment e.g.:

/*
Error: invalid property name
*/
Red text in body:before

The result CSS draws detailed error message in :before pseudo-class of body element e.g.:

body:before {
    content: 'Error: invalid property name';
    color: maroon;
    background-color: white;
}

In most cases you could be aware of syntax error by refreshing your working document because it will removes all other styles and leaves only a red text.

logging

It logs syntax errors if exist during compilation to sassutils.wsgi.SassMiddleware logger with level ERROR.

To enable this:

from logging import Formatter, StreamHandler, getLogger
logger = getLogger('sassutils.wsgi.SassMiddleware')
handler = StreamHandler(level=logging.ERROR)
formatter = Formatter(fmt='*' * 80 + '\n%(message)s\n' + '*' * 80)
handler.setFormatter(formatter)
logger.addHandler(handler)

Or simply:

import logging
logging.basicConfig()
Parameters
  • app (collections.abc.Callable) -- the WSGI application to wrap
  • manifests (collections.abc.Mapping) -- build settings.  the same format to setup.py script's sass_manifests option
  • package_dir (collections.abc.Mapping) -- optional mapping of package names to directories. the same format to setup.py script's package_dir option

Changed in version 0.4.0: It creates also source map files with filenames followed by .map suffix.

New in version 0.8.0: It logs syntax errors if exist during compilation to sassutils.wsgi.SassMiddleware logger with level ERROR.

static quote_css_string(s)

Quotes a string as CSS string literal.

Credit

Hong Minhee wrote this Python binding of LibSass.

Hampton Catlin and Aaron Leung wrote LibSass, which is portable C/C++ implementation of Sass.

Hampton Catlin originally designed Sass language and wrote the first reference implementation of it in Ruby.

The above three softwares are all distributed under MIT license.

Open Source

GitHub (Git repository + issues)

https://github.com/sass/libsass-python

Azure Pipelines CI (linux + windows)

https://dev.azure.com/asottile/asottile/_build/latest?definitionId=22&branchName=master Build Status.TP Azure Pipelines Coverage (Test coverage) https://dev.azure.com/asottile/asottile/_build/latest?definitionId=22&branchName=master Coverage Status.TP PyPI https://pypi.org/pypi/libsass/ PyPI.TP Changelog changes

Indices and Tables

Author

Hong Minhee

Info

Jan 27, 2021 0.20.0 libsass