def get_webassets_env_from_settings(settings, prefix='webassets'):
    """This function will take all webassets.* parameters, and
    call the ``Environment()`` constructor with kwargs passed in.

    The only two parameters that are not passed as keywords are:

    * base_dir
    * base_url

    which are passed in positionally.

    Read the ``WebAssets`` docs for ``Environment`` for more details.
    """
    # Make a dictionary of the webassets.* elements...
    kwargs = {}   # assets settings
    cut_prefix = len(prefix) + 1
    for k in settings:
        if k.startswith(prefix):
            val = settings[k]
            if isinstance(val, six.string_types):
                if val.lower() in auto_booly:
                    val = asbool(val)
                elif val.lower().startswith('json:') and k[cut_prefix:] != 'manifest':
                    val = json.loads(val[5:])
            kwargs[k[cut_prefix:]] = val

    if 'base_dir' not in kwargs:
        raise Exception("You need to provide webassets.base_dir in your configuration")
    if 'base_url' not in kwargs:
        raise Exception("You need to provide webassets.base_url in your configuration")

    asset_dir = kwargs.pop('base_dir')
    asset_url = kwargs.pop('base_url')

    if ':' in asset_dir:
        try:
            resolved_dir = AssetResolver(None).resolve(asset_dir).abspath()
        except __HOLE__:
            pass
        else:
            # Store the original asset spec to use later
            kwargs['asset_base'] = asset_dir
            asset_dir = resolved_dir

    if not asset_url.startswith('/'):
        if six.moves.urllib.parse.urlparse(asset_url).scheme == '':
            asset_url = '/' + asset_url

    if 'debug' in kwargs:
        kwargs['debug'] = maybebool(kwargs['debug'])

    if 'cache' in kwargs:
        cache = kwargs['cache'] = maybebool(kwargs['cache'])

        if cache and isinstance(cache, six.string_types) and not path.isdir(cache):
            makedirs(cache)

    # 'updater' is just passed in...

    if 'auto_build' in kwargs:
        kwargs['auto_build'] = maybebool(kwargs['auto_build'])

    if 'jst_compiler' in kwargs:
        kwargs['JST_COMPILER'] = kwargs.pop('jst_compiler')

    if 'jst_namespace' in kwargs:
        kwargs['JST_NAMESPACE'] = kwargs.pop('jst_namespace')

    if 'manifest' in kwargs:
        kwargs['manifest'] = maybebool(kwargs['manifest'])

    if 'url_expire' in kwargs:
        kwargs['url_expire'] = maybebool(kwargs['url_expire'])

    if 'static_view' in kwargs:
        kwargs['static_view'] = asbool(kwargs['static_view'])
    else:
        kwargs['static_view'] = False

    if 'cache_max_age' in kwargs:
        kwargs['cache_max_age'] = int(kwargs.pop('cache_max_age'))
    else:
        kwargs['cache_max_age'] = None

    if 'load_path' in kwargs:
        # force load_path to be an array and split on whitespace
        if not isinstance(kwargs['load_path'], list):
            kwargs['load_path'] = kwargs['load_path'].split()

    paths = kwargs.pop('paths', None)

    if 'bundles' in kwargs:
        if isinstance(kwargs['bundles'], six.string_types):
            kwargs['bundles'] = kwargs['bundles'].split()

    bundles = kwargs.pop('bundles', None)

    assets_env = Environment(asset_dir, asset_url, **kwargs)

    if paths is not None:
        for map_path, map_url in json.loads(paths).items():
            assets_env.append_path(map_path, map_url)

    def yaml_stream(fname, mode):
        if path.exists(fname):
            return open(fname, mode)
        else:
            return assets_env.resolver.resolver.resolve(fname).stream()

    if isinstance(bundles, list):
        fnames = reversed(bundles)
        fin = fileinput.input(fnames, openhook=yaml_stream)
        with closing(fin):
            lines = [text(line).rstrip() for line in fin]
        yamlin = six.StringIO('\n'.join(lines))
        loader = YAMLLoader(yamlin)
        result = loader.load_bundles()
        assets_env.register(result)
    elif isinstance(bundles, dict):
        assets_env.register(bundles)

    return assets_env
dataset/ETHPy150Open sontek/pyramid_webassets/pyramid_webassets/__init__.py/get_webassets_env_from_settings