r'''
    Ensure that a path is a zip file by:
     - checking length is 1
     - checking extension is '.zip'

def is_zip_file(models):
    r'''
    Ensure that a path is a zip file by:
     - checking length is 1
     - checking extension is '.zip'
    '''
    ext = os.path.splitext(models[0])[1]
    return (len(models) == 1) and (ext == '.zip')