基于Flask做web开发免不了需要有下载数据的功能,在此就把一些走过的弯路记录下
前期准备:
1.安装node.js
$wget https://nodejs.org/dist/v10.9.0/node-v10.9.0-linux-x64.tar.xz
$xz -d node-v10.9.0-linux-x64.tar.xz
$tar -xf node-v10.9.0-linux-x64.tar
$cd node-v10.9.0-linux-x64/
$./bin/node -v
v10.9.0
打开bashrc添加路径:export PATH=$PATH:/home/chris/node/node-v10.9.0-linux-x64/bin,然后$source ~/.bashrc
2.安装json2csv
$mkdir package.json
$npm install json2csv --save 下载json2csv到node_modules中
参考资料:https://www.runoob.com/nodejs/nodejs-install-setup.html https://github.com/boychina/json2csv
或者跳过此步,直接使用github上作者附带的json2csv文件:https://github.com/boychina/json2csv/tree/master/dist
一、普通下载
此功能在HTML上设置下载按钮,把后端传递到前端的json数据下载下来(数据也可以全部放前端,放后端安全点)
app.py
from flask import Flask,render_template
app = Flask(__name__)
@app.route("/demo", methods=['POST','GET'])
def demo():
data=[{'a':1,'b':2,'c':3},{'a':4,'b':5,'c':6}]
return render_template('demo.html',data=data)
if __name__ == '__main__':
app.run(debug=True, host='0.0.0.0', port=9875)
templates/demo.html
<p><input type="button" value="Download"></p>
<script src="static/json2csv.js" type="text/javascript" charset="utf-8"></script>
<script charset="utf-8">
var fields = ["a","b","c"]
var tt={{data|safe}}
console.log(tt)
var csv = json2csv({ data: tt, fields: fields });
console.log(csv)
var eleButton = document.querySelector('input[type="button"]');
// 下载文件方法
var funDownload = function (content, filename) {
var eleLink = document.createElement('a');
eleLink.download = filename;
eleLink.style.display = 'none';
// 字符内容转变成blob地址
data = "\ufeff"+content;
var blob = new Blob([data]);
eleLink.href = URL.createObjectURL(blob);
// 触发点击
document.body.appendChild(eleLink);
eleLink.click();
// 然后移除
document.body.removeChild(eleLink);};
eleButton.addEventListener('click', function () {funDownload(csv, 'test.csv');});
</script>
二、跳转链接下载
在前端HTML点下按钮的时候,跳出要下载数据的界面框
app.py:
from flask import Flask,render_template,Response
app = Flask(__name__)
@app.route("/demo", methods=['POST','GET'])
def demo():
return render_template('demo.html')
@app.route("/getcsv")
def getcsv():
table='a,b,c,\n1,2,3,\n4,5,6'
return Response(table,mimetype="text/csv",headers={"Content-disposition":"attachment; filename=getcsv.csv"})
if __name__ == '__main__':
app.run(debug=True, host='0.0.0.0', port=9875)
templates/demo.html:
<div style="width:10%;float:left"><form method="get" action="/getcsv">
<button type="submit">Download</button></form></div>
这是目前想到在flask框架下实现的下载功能,如果有更好的方法,可以互相交流下,谢谢
代码可以参考我的github:https://github.com/Cherishsword/Test-Download