from os.path import expanduser, expandvars, isdir
sites_path = ["${QP_SITES}", "~/qp_sites", "~/.qp_sites", '/var/qp_sites']
sites_path += __path__

__path__ = []
for raw_path in sites_path:
    path = expanduser(expandvars(raw_path))
    if isdir(path):
        __path__.append(path)