To display progress bar and percentage when downloading with boto3

boto3_progress_bar.py

class ProgressPercentage(object):
    ''' Progress Class
    Class for calculating and displaying download progress
    '''
    def __init__(self, client, bucket, filename):
        ''' Initialize
        initialize with: file name, file size and lock.
        Set seen_so_far to 0. Set progress bar length
        '''
        self._filename = filename
        self._size = client.head_object(Bucket=bucket, Key=filename)['ContentLength']
        self._seen_so_far = 0
        self._lock = threading.Lock()
        self.prog_bar_len = 80

    def __call__(self, bytes_amount):
        ''' Call
        When called, increments seen_so_far by bytes_amount,
        calculates percentage of seen_so_far/total file size 
        and prints progress bar.
        '''
        # To simplify we'll assume this is hooked up to a single filename.
        with self._lock:
            self._seen_so_far += bytes_amount
            ratio = round((float(self._seen_so_far) / float(self._size)) * (self.prog_bar_len - 6), 1)
            current_length = int(round(ratio))

            percentage = round(100 * ratio / (self.prog_bar_len - 6), 1)

            bars = '+' * current_length
            output = bars + ' ' * (self.prog_bar_len - current_length - len(str(percentage)) - 1) + str(percentage) + '%'

            if self._seen_so_far != self._size:
                sys.stdout.write(output + '\r')
            else:
                sys.stdout.write(output + '\n')
            sys.stdout.flush()
            
## Example usage
import boto3
s3 = boto3.resource('s3')
progress = ProgressPercentage(client, BUCKET_NAME, FILE_NAME)
s3.Bucket(BUCKET_NAME).download_file(FILE_NAME, DEST_NAME, Callback=progress)

thank you for that.