Function to retreive all keys in a shelve
    Args:
        file_name: Shelve storage file name
        file_location: The location of the file, derive from the os module

    Returns:
        a list of the keys

def get_keys_from_shelve(file_name, file_location):
    """
    Function to retreive all keys in a shelve
    Args:
        file_name: Shelve storage file name
        file_location: The location of the file, derive from the os module

    Returns:
        a list of the keys

    """
    temp_list = list()
    file = __os.path.join(file_location, file_name)
    shelve_store = __shelve.open(file)
    for key in shelve_store:
        temp_list.append(key)
    shelve_store.close()
    return temp_list