使用 Flask 上传文件时出现内部服务器错误

Question

我正在使用 CS50 IDE 和 Flask 开发一个 Web 应用程序。我希望用户上传带有表单的文件。但是当表单提交时，我得到一个“500 Internal Server Error”，无论文件是否被选中。

如果选择了文件，则控制台中没有错误日志。

如果选择NO文件，有如下错误日志：

ERROR:application:Exception on /new-item [POST]
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 2446, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 1951, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 1820, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python3.7/site-packages/flask/_compat.py", line 39, in reraise
    raise value
  File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 1949, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 1935, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/home/ubuntu/final-project/helpers.py", line 34, in decorated_function
    return f(*args, **kwargs)
  File "/home/ubuntu/final-project/application.py", line 45, in decorated_function
    return f(*args, **kwargs)
  File "/home/ubuntu/final-project/application.py", line 350, in newItem
    file.save(os.path.join(app.config['IMAGE_UPLOADS'], filename))
  File "/usr/local/lib/python3.7/site-packages/werkzeug/datastructures.py", line 2800, in save
    dst = open(dst, "wb")
IsADirectoryError: [Errno 21] Is a directory: 'static/img/menu/'

烧瓶代码

app.config["IMAGE_UPLOADS"] = "static/img/menu/"

@app.route("/new-item", methods=['GET', 'POST'])
def newItem():
    if request.method == "POST":

        if request.files:
            file = request.files["file"]
            filename = secure_filename(file.filename)
            file.save(os.path.join(app.config['IMAGE_UPLOADS'], filename))

HTML 代码

<form action="/new-item" method="post" enctype="multipart/form-data">
    <div>
        <input type="file" name="file">
        <label>Choose Image</label>
    </div>
    <button type="submit">Submit</button>
</form>

知道是什么导致了错误吗？

Answer 1

你需要去掉尾部斜杠，这是对os.path.join的误用

app.config["IMAGE_UPLOADS"] = "static/img/menu" # drop the trailing slash

见Why doesn't os.path.join() work in this case?

您可能还需要将app.config["IMAGE_UPLOADS"] 更新为绝对路径而不是相对路径。