Flask Web开发入门北京快乐8出售之文件上传

本章北京快乐8出售 dsluntan.com 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
@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
<div class="layui-inline">
<label class="layui-form-label">上传文件</label>
<div class="layui-input-inline">
<input type="text" name="attach" id="upload_message" lay-verify="required" autocomplete="off"
class="layui-input" readonly="readonly">
</div>
</div>
<div class="layui-inline">
<img id='img_delete' src="{{ url_for('static', filename='images/delete.png')}}" onclick="do_delete()"
style="display: none;">
<button type="button" class="layui-btn" id="upload"><i class="layui-icon"></i>上传文件</button>

    </div>

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
function do_delete() {
var filename = $("#upload_message").val();
layui.use(['upload', 'layer'], function () {
var layer = layui.layer;
$.ajax({
url: '/delete?filename=' + filename + "&timestamp=" + new Date().getTime()
, type: 'GET'
, success: function (response) {
console.log(response)
if (response.code == 0) {
layer.msg('"' + filename + '"删除成功！');
$("#upload_message").val('')
$("img_delete").hide()
} else {
layer.msg('"' + filename + '"删除失败！');
}
}
})
})
}