def scary_path(path):
    """Whitelist the WORKON_HOME strings we're willing to substitute in
    to strings that we provide for user's shell to evaluate.

    If it smells at all bad, return True.
    """
    if not path:
        return True
    assert isinstance(path, bytes)
    return not NOT_SCARY.match(path)
Whitelist the WORKON_HOME strings we're willing to substitute in
    to strings that we provide for user's shell to evaluate.

    If it smells at all bad, return True.