Flask Web开发入门（八）之文件上传

落日映苍穹つ 2022-06-02 10:26 214阅读 0赞

本章我们介绍Flask Web开发中涉及的文件上传模块

### **定义后台接收处理逻辑** ###

# http://flask.pocoo.org/docs/0.12/patterns/fileuploads/
    @app.route('/upload', methods=['POST'])
    def upload_file():
        if request.method == 'POST':
            # check if the post request has the file part
            if 'file' not in request.files:
                logger.debug('No file part')
                return jsonify({
       'code': -1, 'filename': '', 'msg': 'No file part'})
            file = request.files['file']
            # if user does not select file, browser also submit a empty part without filename
            if file.filename == '':
                logger.debug('No selected file')
                return jsonify({
       'code': -1, 'filename': '', 'msg': 'No selected file'})
            else:
                try:
                    if file and allowed_file(file.filename):
                        origin_file_name = file.filename
                        logger.debug('filename is %s' % origin_file_name)
                        # filename = secure_filename(file.filename)
                        filename = origin_file_name
    
                        if os.path.exists(UPLOAD_PATH):
                            logger.debug('%s path exist' % UPLOAD_PATH)
                            pass
                        else:
                            logger.debug('%s path not exist, do make dir' % UPLOAD_PATH)
                            os.makedirs(UPLOAD_PATH)
    
                        file.save(os.path.join(UPLOAD_PATH, filename))
                        logger.debug('%s save successfully' % filename)
                        return jsonify({
       'code': 0, 'filename': origin_file_name, 'msg': ''})
                    else:
                        logger.debug('%s not allowed' % file.filename)
                        return jsonify({
       'code': -1, 'filename': '', 'msg': 'File not allowed'})
                except Exception as e:
                    logger.debug('upload file exception: %s' % e)
                    return jsonify({
       'code': -1, 'filename': '', 'msg': 'Error occurred'})
        else:
            return jsonify({
       'code': -1, 'filename': '', 'msg': 'Method not allowed'})

### **判定文件类型** ###

def allowed_file(filename):
        return '.' in filename and \
               filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS

### **前台页面代码** ###

### **上传按钮初始化及回调** ###

layui.use(['upload', 'layer'], function () { 
            var upload = layui.upload;
            var layer = layui.layer;
            upload.render({
                elem: '#upload'
                , url: '/upload'
                , accept: 'file'
                , exts: 'txt'
                , size: 2048
                , done: function (res) { 
                    console.log(res);
                    if (res.code === 0) {
                        layer.msg(res.filename + '上传成功');
                        $("#upload_message").val(res.filename);
                        $("#img_delete").show()
                    } else {
                        layer.alert('上传失败');
                        $("#upload_message").val('上传失败！');
                    }
                }
            });
        })

### **当然允许上传，同时也应该允许对以删除文件进行删除** ###

@app.route('/delete', methods=['GET'])
    def delete_file():
        if request.method == 'GET':
            filename = request.args.get('filename')
            timestamp = request.args.get('timestamp')
            logger.debug('delete file : %s, timestamp is %s' % (filename, timestamp))
            try:
                fullfile = os.path.join(UPLOAD_PATH, filename)
    
                if os.path.exists(fullfile):
                    os.remove(fullfile)
                    logger.debug("%s removed successfully" % fullfile)
                    return jsonify({
       'code': 0, 'msg': ''})
                else:
                    return jsonify({
       'code': -1, 'msg': 'File not exist'})
    
            except Exception as e:
                logger.debug("delete file error %s" % e)
                return jsonify({
       'code': -1, 'msg': 'File deleted error'})
    
        else:
            return jsonify({
       'code': -1, 'msg': 'Method not allowed'})

### **删除按钮初始化及回调处理** ###

### **实现效果** ###

![这里写图片描述][SouthEast]

**源码参考**：[https://github.com/ypmc/flask-sqlalchemy-web][https_github.com_ypmc_flask-sqlalchemy-web]

[SouthEast]: /images/20220602/91f4985a07214b96b92cc28d75ba5276.png
[https_github.com_ypmc_flask-sqlalchemy-web]: https://github.com/ypmc/flask-sqlalchemy-web