def select_newest_project(dx_project_ids):
    """
    Given a list of DNAnexus project IDs, returns the one that is newest as determined by creation date.
  
    Args: 
        dx_project_ids: `list` of DNAnexus project IDs.
  
    Returns:
        `str`.
    """
    if len(dx_project_ids) == 1:
        return dx_project_ids[0]
    
    projects = [dxpy.DXProject(x) for x in dx_project_ids]
    created_times = [x.describe()["created"] for x in projects]
    paired = zip(created_times,projects)
    paired.sort(reverse=True)
    return paired[0][0]