def paddingLength(str_len, blocksize=AES_blocksize):
  ''' Function to calculate the length of the required padding
  Input: (int) str_len   - String length of the text 
         (int) blocksize - block size of the algorithm    
  Returns: (int) number of required pad bytes for string of size.'''
  assert 0 < blocksize < 255, 'blocksize must be between 0 and 255'
  assert str_len > 0 , 'string length should be non-negative'
  
  'If the last block is already full, append an extra block of padding'
  pad_len = blocksize - (str_len % blocksize)
  
  return pad_len
dataset/ETHPy150Open keenlabs/KeenClient-Python/keen/Padding.py/paddingLength/original