code: def read_as_base64(fn):
      
      with open(fn) as unpacked_file:
          with tempfile.TemporaryFile() as b64_file:
              base64.encode(unpacked_file, b64_file)
              b64_file.flush()
  
              b64_file.seek(0)
              return b64_file.read()
docs: Convert given `fn` to base64 and return it. This method does the process
      in not-so-much memory consuming way.
  
      Args:
          fn (str): Path to the file which should be converted.
  
      Returns:
          str: File encoded as base64.