How to submit multiple files with the same POST name with requests?

Question

With requests, when using POST with simple data, I can use the same name for multiple values. The CURL command:

curl --data "source=contents1&source=contents2" example.com

can be translated to:

data = {'source': ['contents1', 'contents2']}
requests.post('example.com', data)

The same doesn't work with files. If I translate the working CURL command:

curl --form "source=@./file1.txt" --form "source=@./file2.txt" example.com

to:

with open('file1.txt') as f1, open('file2.txt') as f2:
    files = {'source': [f1, f2]}
    requests.post('example.com', files=files)

only the last file is received.

MultiDict from werkzeug.datastructures doesn't help either.

How to submit multiple files with the same POST name?

Answer 1

Don't use a dictionary, use a list of tuples; each tuple a (name, file) pair:

files = [('source', f1), ('source', f2)]

The file element can be another tuple with more detail about the file; to include a filename and the mimetype, you can do:

files = [
    ('source', ('f1.ext', f1, 'application/x-example-mimetype'),
    ('source', ('f2.ext', f2, 'application/x-example-mimetype'),
]

This is documented in the POST Multiple Multipart-Encoded Files section of the Advanced Usage chapter of the documentation.