flask 文件转为pdf并添加二维码

背景：

宝安区需求，企业会下载表格，打印后填报。填报后收上表格，统一录入PDA。因为某台PDA只能录某个地方的表格，所以他们希望纸质表上有个二维码，扫描出现填报公司的一些信息，以及统计（好像是这样，没文档，口头说的）。

访问文件下载接口，传入user_id,就能下载到带有user_id二维码的问卷，扫描二维码，会出现一个信息页面，点击完成按钮，会将该公司状态更新为完成。

很小的项目，从头到尾简单纪录一下

整个项目

 flask框架：main.py

import sys, time, os
from util import *
from flask import Flask, jsonify, g, make_response, send_from_directory, request, render_template
from flask_cors import CORS
reload(sys)
sys.setdefaultencoding('utf8')

app = Flask(__name__)
app.app_context().push()

@app.before_request
def before_request():
    pass

@app.after_request
def after_request(response):
    response.headers['Access-Control-Allow-Origin'] = '*'#处理跨域
    return response

@app.route('/report/down')
def down():
    user_id = request.args['user_id']
    count(user_id, 'down')
    file_name = mergePdf(user_id)
    remove_file(file_name)
    return send_from_directory(os.getcwd(), file_name, as_attachment=True)

@app.route('/report/complete')
def complete():
    user_id = request.args['user_id']
    count(user_id, 'complete')
    return jsonify({})

@app.route('/report/detail')
def detail():
    info = reportInfo()
    info['noComplete'] = info['len']-info['down']
    info['area_name'] = '西乡街道'#暂时写死
    info['user_id'] = request.args['user_id']
    return render_template("result.html", info=info)

@app.route('/report/report_info')
def report_info():
    return jsonify(reportInfo())

def runFlask(port):
    app.run(host='0.0.0.0', port=port, threaded=True)#异步请求
    CORS(app, supports_credentials=True)

if '__main__' == __name__:
    runFlask(9090)

主要方法：util.py

生成pdf这块做得比较麻烦（有其他方法请跟我说）

画布生成pdf，先画表格图片，再画二维码图片

二维码是浮在原文件左上角，好像只能用画布的形式才能生成，而画布生成的pdf只有一页（就算设置了pageSize，打印的时候也只有一页），所以生成了多个pdf，最后再合并的

import qrcode, PyPDF2, codecs, os, time
from threading import Thread
from config import MRedis
from reportlab.lib.pagesizes import letter, A4
from reportlab.lib.units import inch
from reportlab.pdfgen import canvas

def async(f):
    def wrapper(*args, **kwargs):
        thr = Thread(target = f, args = args, kwargs = kwargs)
        thr.start()
    return wrapper

def count(user_id, status):
    MRedis.hset("reportCount", user_id, status)

def reportInfo():
    result = {
        'down': 0,
        'complete': 0
    }
    obj_name = "reportCount"
    keys = MRedis.hkeys(obj_name)
    for i in keys:
        status = MRedis.hget(obj_name, i)
        result[status] = result[status]+1
    result['len'] = len(keys)
    return result

def getQRCode(user_id):
    qr=qrcode.QRCode(version = 2,error_correction = qrcode.constants.ERROR_CORRECT_L,box_size=10,)
    qr.add_data('http://服务器/report/detail?user_id='+user_id)
    # qr.add_data('http://10.0.0.17:9090/report/detail?user_id='+user_id)
    qr.make(fit=True)
    img = qr.make_image()
    img_name = getQRName(user_id)
    img.save(img_name)
    return img_name

def getQRName(user_id):
    return user_id+'.png'

def getPdfNameByName(user_id, name):
    return user_id +'_'+ name.split('.')[0]+'.pdf'

def createPdf(user_id, name, path='base_imgs/'):
    width, height = A4
    c = canvas.Canvas(getPdfNameByName(user_id, name), pagesize=A4)
    c.drawImage(path+name, 0, 0, height=height, width=width)
    c.drawImage(getQRCode(user_id), 0 , height-100, height=100, width=100)
    c.save()

@async#10秒后删除文件
def remove_file(path):
    time.sleep(10)
    os.remove(path)

def mergePdf(user_id):
    imgs = {
        0: '611.jpg',
        2: '611-1.jpg',
        3: '611-2.jpg',
        4: '611-3.jpg',
        5: '611-4.jpg',
        6: '611-5.jpg',
        7: '611-6.jpg',
        8: '612.jpg',
    }
    for idx in imgs:
        createPdf(user_id, imgs[idx])

    pdfwriter = PyPDF2.PdfFileWriter()
    pdfreader = PyPDF2.PdfFileReader(open('base_imgs/base.pdf', "rb"))

    fs = {}#文件对象，等写入pdf完成，关闭所有文件流，以做删除
    for page in range(pdfreader.numPages):
        if page in imgs:
            file_path = getPdfNameByName(user_id, imgs[page])
            f = open(file_path, "rb")
            temp = PyPDF2.PdfFileReader(f)
            pdfwriter.addPage(temp.getPage(0))
            fs[file_path] = f
        else:
            pdfwriter.addPage(pdfreader.getPage(page))

    file_name = user_id + '_all.pdf'
    with codecs.open(file_name, 'wb') as f:
        pdfwriter.write(f)

    os.remove(getQRName(user_id))#删除二维码
    for path in fs:
        fs[path].close()#关闭流
        os.remove(path)#删除文件

    return file_name

配置文件：config.py

使用redis中set保存问卷下载状态，某企业下载，往reportCount添加key，key的值分别为down, complete

import redis
pool = redis.ConnectionPool(host='127.0.0.1', port=6379)
MRedis = redis.Redis(connection_pool=pool)

扫描二维码显示页面：templates/result.html

点击按钮，将状态更新为完成

<!DOCTYPE html>
<html>
<head>
    <title>你的信息</title>
    <script src="https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
</head>
<body>
<table>
    <h1>你的信息</h1>
    <h3>法人码：{{info.user_id}}</h3>
    <h3>所属区域：{{info.area_name}}</h3>
    <h1>问卷信息</h1>
    <h3>已下载：{{info.down}}</h3>
    <h3>已完成：{{info.complete}}</h3>
    <h3>未完成：{{info.noComplete}}</h3>
    <button id="completeBtn">已完成问卷上传请点这里</button>
</table>
<script>
function getUrlParam (name){
    var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)")
    var r = window.location.search.substr(1).match(reg)
    if (r !== null)
        return unescape(r[2])
    return null
}
$(document).ready(function(){
    $('#completeBtn').click(function(){
        $.ajax({
            url: 'http://服务器/report/complete?user_id='+getUrlParam('user_id'),
            success: function(obj){
                alert('您的问卷状态已更新为完成！')
                location.reload()
            }
        })
    })
})
</script>
</body>
</html>

nginx转发配置，server内加入

        location /report {
            proxy_pass   http://127.0.0.1:9090/report;
        }

pdf转高清图片

直接用ps转，高清大图

https://jingyan.baidu.com/article/a3f121e4e08725fc9052bb00.html