config.py 文件源码

def process_expansions(dct):
    def expand(val, dct):
        if isinstance(val, six.integer_types) or isinstance(val, bool):
            return val
        if isinstance(val, six.string_types):
            dct2 = copy.deepcopy(dct)
            for env_key, env_val in six.iteritems(os.environ):
                dct2[env_key] = env_val
            return  string.Template(val).safe_substitute(dct2)
        if isinstance(val, list):
            return [expand(x, dct) for x in val]
        if isinstance(val, dict):
            return {k: expand(v,val) for k,v in six.iteritems(val)}
        return val

    for key,val in six.iteritems(dct):
        nval = expand(val, dct)
        dct[key] = nval