How to send a “multipart/form-data” with requests in python?

Question

How to send a multipart/form-data with requests in python? How to send a file, I understand, but how to send the form data by this method can not understand.

Answer 1

Since the previous answers were written, requests have changed. Have a look at the bug thread at Github for more detail and this comment for an example.

In short, the files parameter takes a dict with the key being the name of the form field and the value being either a string or a 2, 3 or 4-length tuple, as described in the section POST a Multipart-Encoded File in the requests quickstart:

>>> url = 'http://httpbin.org/post'
>>> files = {'file': ('report.xls', open('report.xls', 'rb'), 'application/vnd.ms-excel', {'Expires': '0'})}

In the above, the tuple is composed as follows:

(filename, data, content_type, headers)

If the value is just a string, the filename will be the same as the key, as in the following:

>>> files = {'obvius_session_id': '72c2b6f406cdabd578c5fd7598557c52'}

Content-Disposition: form-data; name="obvius_session_id"; filename="obvius_session_id"
Content-Type: application/octet-stream

72c2b6f406cdabd578c5fd7598557c52

If the value is a tuple and the first entry is None the filename property will not be included:

>>> files = {'obvius_session_id': (None, '72c2b6f406cdabd578c5fd7598557c52')}

Content-Disposition: form-data; name="obvius_session_id"
Content-Type: application/octet-stream

72c2b6f406cdabd578c5fd7598557c52