human
Complete the below
def do_rnn_checkpoint(cells, prefix, period=1):

    ''''Make a callback to checkpoint Module to prefix every epoch.
    unpacks weights used by cells before saving.
    Parameters
    cells : RNNCell or list of RNNCells
    The RNN cells used by this symbol.
    prefix : str
    The file prefix to checkpoint to
    period : int
    How many epochs to wait before checkpointing. Default is 1.
    Returns
    callback : function
    The callback function that can be passed as iter_end_callback to fit.'
    '''
 ... Give me a Python code to fix every epoch?
assistant
#Here is Python code to fix every epoch.
    period = int(max(1, period))
    def _callback(iter_no, sym=None, arg=None, aux=None):
        'The    checkpoint    function.'
        if (((iter_no + 1) % period) == 0):
            save_rnn_checkpoint(cells, prefix, (iter_no + 1), sym, arg, aux)
    return _callback