python requests file upload

I'm performing a simple task of uploading a file using Python requests library. I searched Stack Overflow and no one seemed to have the same problem, namely, that the file is not received by the server:

import requests
url='http://nesssi.cacr.caltech.edu/cgi-bin/getmulticonedb_release2.cgi/post'
files={'files': open('file.txt','rb')}
values={'upload_file' : 'file.txt' , 'DB':'photcat' , 'OUT':'csv' , 'SHORT':'short'}
r=requests.post(url,files=files,data=values)


I'm filling the value of 'upload_file' keyword with my filename, because if I leave it blank, it says

Error - You must select a file to upload!


And now I get

File file.txt of size bytes is uploaded successfully!
Query service results: There were 0 lines.


Which comes up only if the file is empty. So I'm stuck as to how to send my file successfully. I know that the file works because if I go to this website and manually fill in the form it returns a nice list of matched objects, which is what I'm after. I'd really appreciate all hints.

Some other threads related (but not answering my problem):

1 Answer
1

If upload_file is meant to be the file, use:

upload_file

files = {'upload_file': open('file.txt','rb')}
values = {'DB': 'photcat', 'OUT': 'csv', 'SHORT': 'short'}

r = requests.post(url, files=files, data=values)


and requests will send a multi-part form POST body with the upload_file field set to the contents of the file.txt file.

requests

upload_file

file.txt

The filename will be included in the mime header for the specific field:

>>> import requests
>>> open('file.txt', 'wb') # create an empty demo file
<_io.BufferedWriter name='file.txt'>
>>> files = {'upload_file': open('file.txt', 'rb')}
>>> print(requests.Request('POST', 'http://example.com', files=files).prepare().body.decode('ascii'))
--c226ce13d09842658ffbd31e0563c6bd
Content-Disposition: form-data; name="upload_file"; filename="file.txt"


--c226ce13d09842658ffbd31e0563c6bd--


Note the filename="file.txt" parameter.

filename="file.txt"

files = [('attachment', open('attachment1.txt', 'rb')), ('attachment', open('attachment2.txt', 'rb'))]

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