python导出文件返回字节流

问题：导出文件时，如何将字节流返回给前端，前端通过blob方式获取

方法：
Tornado

import xlwt
from io import BytesIO

class ApiDownloadHandler(BaseHandler):
    @login_required()
    def post(self):
        # 设置响应头
        self.set_header('Content-Type', 'application/x-xls')
        # filename 不能为中文
        self.set_header('Content-Disposition', 'attachment; filename=download.xls')
        wb = xlwt.Workbook()
        ws = wb.add_sheet('Sheet1')
        style0 = xlwt.easyxf('font: name Microsoft YaHei Light, height 220; align: vert centre, horiz center')
        # title
        header = ['序号', '姓名', '年龄']
        for i in range(len(header)):
            ws.write(0, i, header[i], style0)
            ws.col(i).width = 4000
        sio = BytesIO()
        # 这点很重要，传给save函数的不是保存文件名，而是一个StringIO流
        wb.save(sio)
        self.write(sio.getvalue())

FastAPI

from io import BytesIO
from fastapi.responses import StreamingResponse

@router.post(
    path='/api/export/students',
    name='导出学生列表',
    description='根据条件筛选学生，并导出为excel文件')
async def export_students(
    schema_data: StudentSearchSchema,
    db: AsyncSession=Depends(get_async_db),
    current_user: UserSchema = Depends(permission('学生基础信息管理', ['operate']))
    ):
    # 将数据写入excel
    wb = xlwt.Workbook()
    ws = wb.add_sheet('Sheet1')
    style_header = xlwt.easyxf('font: name Microsoft YaHei Light, height 220, bold true; align: vert centre, horiz left')
    style0 = xlwt.easyxf('font: name Microsoft YaHei Light, height 220; align: vert centre, horiz left')
    header = ['姓名', '曾用名', '性别']
    for i in range(len(header)):
        ws.write(0, i, header[i], style_header)
    sio = BytesIO()
    wb.save(sio)
    return StreamingResponse(BytesIO(sio.getvalue()))

参考：

https://blog.csdn.net/x1131230123/article/details/134832957