'Return list of config files, from environment or standard.'

def get_standard_config_files(self):

    try:
        config_files = os.environ['DOCUTILSCONFIG'].split(os.pathsep)
    except KeyError:
        config_files = self.standard_config_files
    expand = os.path.expanduser
    if ('HOME' not in os.environ):
        try:
            import pwd
        except ImportError:
            expand = (lambda x: x)
    return [expand(f) for f in config_files if f.strip()]
