def accumulator(init, update):
    return (
        init + len(update)
            if isinstance(init, int) else
        init + update
    )
Copy characters from the margin screen to the real screen.
dataset/ETHPy150Open jjangsangy/py-translate/translate/coroutines.py/accumulator--crossover with--dataset/ETHPy150Open jonathanslenders/python-prompt-toolkit/prompt_toolkit/layout/containers.py/Window._copy_margin