How to multi-user POST list of JSON / xml files using python requests

Don't use a dictionary, use a list of tuples (key, value)

for your query parameters:

params = [('title', 'file1'), ('title', 'file2'), ('title', 'file3')]

      

        
        
        
      

    

otherwise you will only get one key.

You don't have to set a title Content-Type

; requests

will set it correctly for you when you use the parameter files

; this will also include the correct border. You should never set the border directly, really:

params = [('title', 'file1'), ('title', 'file2'), ('title', 'file3')]
r = requests.post('http://example.com', 
                  files=files, headers=headers, params=params)

      

        
        
        
      

    

You can set headers for each part of the file by adding a fourth element to the root file for additional headers, but in this case you should not try to set the header yourself Content-Disposition

; it will still be overwritten.

Introspection of the prepared request object then gives you:

>>> import requests
>>> from pprint import pprint
>>> files = {'file1': ('foo.txt', 'foo\ncontents\n','text/plain'), 
...           'file2': ('bar.txt', 'bar contents', 'text/plain'),
...           'file3': ('baz.txt', 'baz contents', 'text/plain')}
>>> headers = {'Content-Disposition': 'attachment'}
>>> params = [('title', 'file1'), ('title', 'file2'), ('title', 'file3')]
>>> r = requests.Request('POST', 'http://example.com',
...                      files=files, headers=headers, params=params)
>>> prepared = r.prepare()
>>> prepared.url
'http://example.com/?title=file1&title=file2&title=file3'
>>> pprint(dict(prepared.headers))
{'Content-Disposition': 'attachment',
 'Content-Length': '471',
 'Content-Type': 'multipart/form-data; boundary=7312ccd96db94419bf1d97f2c54bbad1'}
>>> print prepared.body
--7312ccd96db94419bf1d97f2c54bbad1
Content-Disposition: form-data; name="file3"; filename="baz.txt"
Content-Type: text/plain

baz contents
--7312ccd96db94419bf1d97f2c54bbad1
Content-Disposition: form-data; name="file2"; filename="bar.txt"
Content-Type: text/plain

bar contents
--7312ccd96db94419bf1d97f2c54bbad1
Content-Disposition: form-data; name="file1"; filename="foo.txt"
Content-Type: text/plain

foo
contents

--7312ccd96db94419bf1d97f2c54bbad1--

      

        
        
        
      

    

If you absolutely must have multipart/mixed

and not multipart/form-data

, you will need to build the POST body yourself and set the headers from it. The included urllib3

tools should be able to do this for you:

from requests.packages.urllib3.fields import RequestField
from requests.packages.urllib3.filepost import encode_multipart_formdata

fields = []    
for name, (filename, contents, mimetype) in files.items():
    rf = RequestField(name=name, data=contents,
                      filename=filename)
    rf.make_multipart(content_disposition='attachment', content_type=mimetype)
    fields.append(rf)

post_body, content_type = encode_multipart_formdata(fields)
content_type = ''.join(('multipart/mixed',) + content_type.partition(';')[1:])

headers = {'Content-Type': content_type}
requests.post('http://example.com', data=post_body, headers=headers, params=params)

      

        
        
        
      

    

or you can use a email

package to do the same:

from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

body = MIMEMultipart()
for name, (filename, contents, mimetype) in files.items():
    part = MIMEText(contents, _subtype=mimetype.partition('/')[-1], _charset='utf8')
    part.add_header('Content-Disposition', 'attachment', filename=filename)
    body.attach(part)

post_body = body.as_string().partition('\n\n')[-1]
content_type = body['content-type']

headers = {'Content-Type': content_type}
requests.post('http://example.com', data=post_body, headers=headers, params=params)

      

        
        
        
      

    

but please note that this method assumes that you set the character set (I assumed UTF-8 for JSON and XML) and that it will most likely use Base64 encoding for the content:

>>> body = MIMEMultipart()
>>> for name, (filename, contents, mimetype) in files.items():
...     part = MIMEText(contents, _subtype=mimetype.partition('/')[-1], _charset='utf8')
...     part.add_header('Content-Disposition', 'attachment', filename=filename)
...     body.attach(part)
... 
>>> post_body = body.as_string().partition('\n\n')[-1]
>>> content_type = body['content-type']
>>> print post_body
--===============1364782689914852112==
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="baz.txt"

YmF6IGNvbnRlbnRz

--===============1364782689914852112==
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="bar.txt"

YmFyIGNvbnRlbnRz

--===============1364782689914852112==
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="foo.txt"

Zm9vCmNvbnRlbnRzCg==

--===============1364782689914852112==--

>>> print content_type
multipart/mixed; boundary="===============1364782689914852112=="