python - 生成器函数的返回类型提示是什么？

Question

我正在尝试为生成器函数编写 :rtype: 类型提示。它返回的类型是什么？

例如，假设我有这个产生字符串的函数:

def read_text_file(fn):
    """
    Yields the lines of the text file one by one.
    :param fn: Path of text file to read.
    :type fn: str
    :rtype: ???????????????? <======================= what goes here?
    """
    with open(fn, 'rt') as text_file:
        for line in text_file:
            yield line

返回类型不仅仅是一个字符串，它是某种可迭代的字符串？所以我不能只写:rtype:str。正确的提示是什么？

Answer 1

Generator

Generator[str, None, None] 或 Iterator[str]