code: def write_to_file(src, dst):
      
      n = 0
      for block in src:
          dst.write(block)
          n += len(block)
      return n
docs: Write data from `src` into `dst`.
  
      Args:
          src (iterable): iterable that yields blocks of data to write
          dst (file-like object): file-like object that must support
              .write(block)
  
      Returns:
          number of bytes written to `dst`