flask-文件上传/下载

曾经终败给现在 2022-07-14 15:12 185阅读 0赞

废话不说，看代码

### 上传文件 ###

import os
    from flask import Flask, render_template, send_from_directory, request, jsonify
    
    app = Flask(__name__)
    
    UPLOAD_FOLDER = 'upload'
    app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER  # 设置文件上传的目标文件夹
    basedir = os.path.abspath(os.path.dirname(__file__))  # 获取当前项目的绝对路径
    ALLOWED_EXTENSIONS = set(['txt', 'png', 'jpg', 'xls', 'JPG', 'PNG', 'xlsx', 'gif', 'GIF'])  # 允许上传的文件后缀
    
    # 判断文件是否合法
    def allowed_file(filename):
        return '.' in filename and filename.rsplit('.', 1)[1] in ALLOWED_EXTENSIONS
    
    # 具有上传功能的页面
    @app.route('/test/upload')
    def upload_test():
        return render_template('upload.html')
    
    @app.route('/api/upload', methods=['POST'], strict_slashes=False)
    def api_upload():
        file_dir = os.path.join(basedir, app.config['UPLOAD_FOLDER'])  # 拼接成合法文件夹地址
        if not os.path.exists(file_dir):
            os.makedirs(file_dir)  # 文件夹不存在就创建
        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):  # 判断是否是允许上传的文件类型
            fname=f.filename
            ext = fname.rsplit('.', 1)[1]  # 获取文件后缀
            unix_time = int(time.time())
            new_filename = str(unix_time)+'.'+ext   # 修改文件名
            f.save(os.path.join(file_dir, new_filename))  #保存文件到upload目录
    
            return jsonify({
       "errno": 0, "errmsg": "上传成功"})
        else:
            return jsonify({
       "errno": 1001, "errmsg": "上传失败"})

<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
    <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>
    </body>
    </html>

### 来看一下效果 ###

1.  打开上传页  
    ![打开上传页][SouthEast]

2.选择文件  
![选择文件][SouthEast 1]

3.上传成功  
![上传成功][SouthEast 2]  
![上传成功][SouthEast 3]

### 文件下载 ###

@app.route("/download/<path:filename>")
    def downloader(filename):
        dirpath = os.path.join(app.root_path, 'upload')  # 这里是下在目录，从工程的根目录写起，比如你要下载static/js里面的js文件，这里就要写“static/js”
        return send_from_directory(dirpath, filename, as_attachment=True)  # as_attachment=True 一定要写，不然会变成打开，而不是下载

### 看一下效果 ###

1.地址是这样子的  
![地址是这样的][SouthEast 4]  
2.下载完成  
![下载完成][SouthEast 5]

感谢阅读

[SouthEast]: /images/20220714/5f5148e3f1a24ef0abafbca979b4957d.png
[SouthEast 1]: /images/20220714/31d1d6f1141b44689cc327076cbc09f0.png
[SouthEast 2]: /images/20220714/cd6a07faeb074c1ba7d1a484f81a823b.png
[SouthEast 3]: /images/20220714/c70cc265f2af42c5bdd2e8ab5dd8550c.png
[SouthEast 4]: /images/20220714/d7d5ba2a89cd43b988f9b29653ab039d.png
[SouthEast 5]: /images/20220714/c9dac46b22ea4f3b8d4a054193b820fc.png