def read_file(file_path: str) -> str:
    """
    Returns the context of file,by segmented reading
    :param file_path: the target file path
    :return: the file content
    """
    with open(file_path, mode="r", encoding="utf-8") as target:
        length: int = 128
        loop: bool = True
        file_context: str = ""
        while loop:
            try:
                context = target.read(length)
                if not context:
                    break
                file_context += context
            except StopIteration:
                loop = False
                print("Iteration is stopped.")

        return file_context