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

    ''''A callback that saves a model checkpoint every few epochs.
    Each checkpoint is made up of a couple of binary files: a model description file and a
    parameters (weights and biases) file. The model description file is named
    `prefix`--symbol.json and the parameters file is named `prefix`-`epoch_number`.params
    Parameters
    prefix : str
    Prefix for the checkpoint filenames.
    period : int, optional
    Interval (number of epochs) between checkpoints. Default `period` is 1.
    Returns
    callback : function
    A callback function that can be passed as `epoch_end_callback` to fit.
    Example
    >>> module.fit(iterator, num_epoch=n_epoch,
    ... epoch_end_callback  = mx.callback.do_checkpoint("mymodel", 1))
    Start training with [cpu(0)]
    Epoch[0] Resetting Data Iterator
    Epoch[0] Time cost=0.100
    Saved checkpoint to "mymodel-0001.params"
    Epoch[1] Resetting Data Iterator
    Epoch[1] Time cost=0.060
    Saved checkpoint to "mymodel-0002.params"'
    '''

Can you provide a Python code to fix : str?
assistant
#Here is Python code to fix : str
.
    period = int(max(1, period))
    def _callback(iter_no, sym, arg, aux):
        'The    checkpoint    function.'
        if (((iter_no + 1) % period) == 0):
            save_checkpoint(prefix, (iter_no + 1), sym, arg, aux)
    return _callback