class _NotFoundModuleError(Exception): pass
_init_re = re.compile(r'^(.*)\{sep}__init__\.(\w+)$'.format(sep=os.sep))
def import_path(path):
    def _import_module(name):
        try:
            return importlib.import_module(name)
        except ImportError as ex:
            if ex.args[0] == "No module named '{}'".format(name):
                raise _NotFoundModuleError from ex
            raise

    cwd = os.path.abspath(os.path.realpath(os.getcwd()))
    path = os.path.abspath(os.path.realpath(path))

    paths = []
    for p in sys.path:
        p = os.path.abspath(os.path.realpath(p))
        if path.startswith(p):
            paths.append(p)
    if not paths:
        raise ImportError('unable to find module with path {!r}: not in a sys.path'.format(path))

    paths.sort(key=lambda x: len(x), reverse=True)

    init_match = _init_re.match(path)
    if init_match:
        path = init_match.group(1)
    else:
        path = path.rpartition('.')[0]

    was_in_cwd = False
    for syspath in paths:
        if syspath == cwd:
            was_in_cwd = True
            continue

        # Check that syspath is a proper directory prefix,
        # i.e. tail starts with os.sep.
        #
        tail = path[len(syspath.rstrip(os.sep)):]
        if tail[0] != os.sep:
            tail = path

        modname = tail.strip(os.sep).replace(os.sep, '.')
        try:
            return _import_module(modname)
        except _NotFoundModuleError:
            pass

    if was_in_cwd:
        modname = path[len(cwd):].strip(os.sep).replace(os.sep, '.')
        try:
            return _import_module(modname)
        except _NotFoundModuleError:
            pass

    raise ImportError('unable to find module with path {!r}'.format(path))