Flask提供了send_file函數(shù)用來導(dǎo)出文件，以下用實(shí)例來說明

• 路由文件views.py

# 直接調(diào)用該接口即可導(dǎo)出文件
@con.route("/exportExcel", methods=["GET", "POST"])
def export_excel_inter():
    """導(dǎo)出excel報表"""
    return export_excel()

• 實(shí)現(xiàn)

import time
from io import BytesIO
from flask import send_file
from openpyxl import Workbook
from loguru import logger


def export_excel():
    """excel 報表導(dǎo)出"""
    wb = Workbook()
    sheet = wb.create_sheet("報表")

    # excel數(shù)據(jù)處理并設(shè)置樣式
    excel_data_deal(sheet)
    
    # 使用字節(jié)流存儲
    output = BytesIO()
    
    # 保存文件
    wb.save(output)

    # 文件seek位置，從頭(0)開始
    output.seek(0)
    filename = "%s.xls" % str(int(time.time()))

    # 打印文件大小
    logger.info("{} -> {} b".format(filename, len(output.getvalue())))

    # as_attachment：是否在headers中添加Content-Disposition
    # attachment_filename：下載時使用的文件名
    # conditional: 是否支持?jǐn)帱c(diǎn)續(xù)傳
    fv = send_file(output, as_attachment=True, attachment_filename=filename, conditional=True)
    fv.headers['Content-Disposition'] += "; filename*=utf-8''{}".format(filename)
    fv.headers["Cache-Control"] = "no_store"
    fv.headers["max-age"] = 1

    logger.info("導(dǎo)出報表---------%s" % filename)

    return fv

• 注意事項

'''這里創(chuàng)建文件使用openpyxl而不是xlwt，主要是xlwt支持上傳的文件有大小限制，超過會報如下錯誤'''
File "/usr/local/lib/python3.8/site-packages/xlwt/UnicodeUtils.py", line 55, in upack2
    raise Exception('String longer than 32767 characters')
Exception: String longer than 32767 characters


'''Flask靜態(tài)文件默認(rèn)緩存時間為12小時，為了每次導(dǎo)出的文件不是之前緩存的文件，建議清除緩存，如下設(shè)置'''
from datetime import timedelta
app.config['SEND_FILE_MAX_AGE_DEFAULT'] = timedelta(seconds=1)  # 靜態(tài)文件緩存為1s

# Flask默認(rèn)配置源碼
default_config = ImmutableDict(
        {
            "ENV": None,
            "DEBUG": None,
            "TESTING": False,
            "PROPAGATE_EXCEPTIONS": None,
            "PRESERVE_CONTEXT_ON_EXCEPTION": None,
            "SECRET_KEY": None,
            "PERMANENT_SESSION_LIFETIME": timedelta(days=31),
            "USE_X_SENDFILE": False,
            "SERVER_NAME": None,
            "APPLICATION_ROOT": "/",
            "SESSION_COOKIE_NAME": "session",
            "SESSION_COOKIE_DOMAIN": None,
            "SESSION_COOKIE_PATH": None,
            "SESSION_COOKIE_HTTPONLY": True,
            "SESSION_COOKIE_SECURE": False,
            "SESSION_COOKIE_SAMESITE": None,
            "SESSION_REFRESH_EACH_REQUEST": True,
            "MAX_CONTENT_LENGTH": None,
            "SEND_FILE_MAX_AGE_DEFAULT": timedelta(hours=12), # 靜態(tài)文件默認(rèn)緩存時間
            "TRAP_BAD_REQUEST_ERRORS": None,
            "TRAP_HTTP_EXCEPTIONS": False,
            "EXPLAIN_TEMPLATE_LOADING": False,
            "PREFERRED_URL_SCHEME": "http",
            "JSON_AS_ASCII": True,
            "JSON_SORT_KEYS": True,
            "JSONIFY_PRETTYPRINT_REGULAR": False,
            "JSONIFY_MIMETYPE": "application/json",
            "TEMPLATES_AUTO_RELOAD": None,
            "MAX_COOKIE_SIZE": 4093,
        }
)