Flask文档的“样式”部分介绍了将文件流传输到客户端而不将其保存到磁盘的过程，特别是在流传输部分。基本上，您要做的是返回一个Response包装了迭代器的完整对象：

from flask import Response

# construct your app

@app.route("/get-file")
def get_file():
    results = generate_file_data()
    generator = (cell for row in results
                    for cell in row)

    return Response(generator,
                       mimetype="text/plain",
                       headers={"Content-Disposition":
                                    "attachment;filename=test.txt"})