flask文件的上传和下载

文件上传

import base64
import os
import time

from flask import Flask, render_template, request, jsonify, send_from_directory, abort
from werkzeug.utils import secure_filename

app = Flask(__name__)

UPLOAD_FOLDER = 'upload'
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
basedir = os.path.abspath(os.path.dirname(__file__))
ALLOWED_EXTENSIONS = set(['txt', 'png', 'jpg', 'xls', 'JPG', 'PNG', 'xlsx', 'gif', 'GIF'])


# 判断文件的后缀
def allowed_file(filename):
    return '.' in filename and filename.rsplit('.', 1)[1] in ALLOWED_EXTENSIONS


# 用于测试上传
@app.route('/test/upload')
def upload_test():
    return render_template('upload.html')


# 上传文件
@app.route('/api/upload', methods=['POST'], strict_slashes=False)
def api_upload():
    file_dir = os.path.join(basedir, app.config['UPLOAD_FOLDER'])
    if not os.path.exists(file_dir):
        os.makedirs(file_dir)
    f = request.files['myfile']  # 从表单的file字段获取文件，myfile为该表单的name值
    if f and allowed_file(f.filename):
        fname = secure_filename(f.filename)
        print(fname)
        ext = fname.rsplit('.', 1)[1]
        unix_time = int(time.time())
        new_filename = str(unix_time) + '.' + ext
        f.save(os.path.join(file_dir, new_filename))

        return jsonify({"errno": 0, "errmsg": "上传成功"})
    else:
        return jsonify({"errno": 1001, "errmsg": "上传失败"})
if __name__ == '__main__':
    app.run(debug=True)

上面我们写了一个上传接口，我们为了测试这个接口是否工作正常，还得写一个页面（upload.html）：

<form id="form1" method="post" action="/api/upload" enctype="multipart/form-data">
    <div>
        <input id="File1" type="file" name="myfile"/>
        <input type="submit">提交</input>
    </div>
</form>

文件下载

文件下载要比上传简单的多，核心代码如下：

@app.route('/api/download/<filename>', methods=['GET'], strict_slashes=False)
def download(filename):
    if request.method == "GET":
        if os.path.isfile(os.path.join('upload', filename)):
            return send_from_directory('upload', filename, as_attachment=True)
        abort(404)