How do I add a key when posting a image?

[maxf]

I have a issue when posting a file to a server developed by python flask, but always failed with a key error that the key "file" cannot found in request. My question is how to add the key "file" in web post file method?
here is the blocks:

here is the code in server:

You can see that in the server post method, it will get a file object from request.files["file"], but the request does not has this key.

Here is the response error：

400 Bad Request: The browser (or proxy) sent a request that this server could not understand. KeyError: 'file'

I also captured the request raw data:

• Post from inventor:

• Post from HTML form submit
  
  

Welcome any suggestions. Thanks.

[TIMAI2]

Is the server expecting multipart? You cannot send multipart with the web component.

https://pythonbasics.org/flask-upload-file/

[maxf]

Thanks, so any workaround recommend?

[TIMAI2]

Use php instead ?

For example:

METRIC RAT AI2 - POSTing a file to a php server

It may also be that using the customWebView you can upload your files...

[cmt0220]

If I'm not mistaken, there are extensions out there that can encode images in base64. You may consider using such a method to "stringify" your image before POSTing it as text.

[Taifun]

the request header must be a list of key value pairs, i.e. a list of lists...
you currently only have a key value pair, i.e. a simple list

Taifun

[maxf]

Many thanks for the suggestions. I resolved this issue by updating the python server code. use "request.data" to replace with "request.files['file']", after that, key is not required when posting any more.