code: def read_chunks(file, chunk_size=2048, update_func=lambda x: None):
  	
  	while(True):
  		res = file.read(chunk_size)
  		if not res:
  			break
  		update_func(len(res))
  		yield res
docs: Read file in chunks of size chunk_size (or smaller).
  	If update_func is specified, call it on every chunk with the amount
  	read.