Python API

Compiling files

Very basic usage is simple enough:

from scss import Scss
css = Scss()
css.compile("a { color: red + green; }")

Configuration

There are several configuration variables in the scss.config module that you may wish to change.

PROJECT_ROOT: Root of your entire project. Used only to construct defaults for other variables. Defaults to the root of the pyScss installation, which is probably not what you want.

LOAD_PATHS: An iterable of paths to search when using``@import``.

STATIC_ROOT: Used for finding sprite files. Defaults to $PROJECT_ROOT/static.

ASSETS_ROOT: Generated sprites are saved here. Defaults to $STATIC_ROOT/assets.

CACHE_ROOT: Used for storing cached sprite information. Defaults to ASSETS_ROOT.

STATIC_URL: URL equivalent to STATIC_ROOT. Defaults to static/.

ASSETS_URL: URL equivalent to ASSETS_ROOT. Defaults to static/assets/.

SPRTE_MAP_DIRECTION: Direction in which to arrange sprites in a spritesheet. Defaults to vertical; may be changed to horizontal, diagonal, or smart.

VERBOSITY: Increase spew from the compiler. Defaults to 1.

DEBUG: Set to true to make parse errors fatal. Defaults to false.

Warning

Configuration via monkeypatching is fraught with issues. If you don’t need the Compass sprite functionality, stick with passing search_paths to the Scss constructor, and don’t touch these variables at all.

The current plan is to introduce a new mechanism for Compass configuration in 1.3 with deprecation warnings, and remove scss.config entirely in 2.0.

Django example

A rough example of using pyScss with Django:

import os
import fnmatch

import scss

from django.conf import settings
from django.utils.datastructures import SortedDict
from django.contrib.staticfiles import finders


def finder(glob):
    """
    Finds all files in the django finders for a given glob,
    returns the file path, if available, and the django storage object.
    storage objects must implement the File storage API:
    https://docs.djangoproject.com/en/dev/ref/files/storage/
    """
    for finder in finders.get_finders():
        for path, storage in finder.list([]):
            if fnmatch.fnmatchcase(path, glob):
                yield path, storage


# STATIC_ROOT is where pyScss looks for images and static data.
# STATIC_ROOT can be either a fully qualified path name or a "finder"
# iterable function that receives a filename or glob and returns a tuple
# of the file found and its file storage object for each matching file.
# (https://docs.djangoproject.com/en/dev/ref/files/storage/)
scss.config.STATIC_ROOT = finder
scss.config.STATIC_URL = settings.STATIC_URL

# ASSETS_ROOT is where the pyScss outputs the generated files such as spritemaps
# and compile cache:
scss.config.ASSETS_ROOT = os.path.join(settings.MEDIA_ROOT, 'assets/')
scss.config.ASSETS_URL = settings.MEDIA_URL + 'assets/'

# These are the paths pyScss will look ".scss" files on. This can be the path to
# the compass framework or blueprint or compass-recepies, etc.
scss.config.LOAD_PATHS = [
    '/usr/local/www/sass/frameworks/',
    '/Library/Ruby/Gems/1.8/gems/compass-0.11.5/frameworks/compass/stylesheets/',
    '/Library/Ruby/Gems/1.8/gems/compass-0.11.5/frameworks/blueprint/stylesheets/',
]

# This creates the Scss object used to compile SCSS code. In this example,
# _scss_vars will hold the context variables:
_scss_vars = {}
_scss = scss.Scss(
    scss_vars=_scss_vars,
    scss_opts={
        'compress': True,
        'debug_info': True,
    }
)

# 1. Compile from a string:
compiled_css_from_string = _scss.compile('@import "file2"; a {color: red + green; }')

# 2. Compile from a file:
compiled_css_from_file = _scss.compile(scss_file='file1.scss')

# 3. Compile from a set of files (use SortedDict or collections.OrderedDict to
# maintain the compile order):
_scss._scss_files = SortedDict((
    ('file2.scss', open('file2.scss').read()),
    ('file3.scss', open('file3.scss').read()),
    ('file4.scss', open('file4.scss').read()),
))
compiled_css_from_files = _scss.compile()

Note

The API here is likely to be improved in 1.3, to avoid the need for calling underscored functions.

Extending pyScss

There is some support for adding custom functions from Python, but the API is explicitly undocumented and subject to change. Watch this space.