How to upload PDF file using request POST method and requests must be formatted as multipart MIME using python for xeroAPI?

Question

I'm trying to upload PDF-file in the Xero account using the python request library (POST method) and Xeros FilesAPI said "Requests must be formatted as multipart MIME" and have some required fields (link) but I don't how to do that exactly...If I do GET-request I'm getting the list of files in the Xero account but having a problem while posting the file (POST-request)...

My Code:

post_url = 'https://api.xero.com/files.xro/1.0/Files/'
files = {'file': open('/home/mobin/PycharmProjects/s3toxero/data/in_test_upload.pdf', 'rb')}

response = requests.post(
    post_url,
    headers={
        'Authorization': 'Bearer ' + new_tokens[0],
        'Xero-tenant-id': xero_tenant_id,
        'Accept': 'application/json',
        'Content-type': 'multipart/form-data; boundary=JLQPFBPUP0',
        'Content-Length': '1068',
    },
    files=files,
)

json_response = response.json()

print(f'Uploading Responsoe ==> {json_response}')
print(f'Uploading Responsoe ==> {response}')

Error Mesage/Response:

Uploading Responsoe ==> [{'type': 'Validation', 'title': 'Validation failure', 'detail': 'No file is was attached'}]
Uploading Responsoe ==> <Response [400]>

Answer 1

As I see you're improperly set the boundary. You set it in the headers but not tell to requests library to use custom boundary. Let me show you an example:

>>> import requests
>>> post_url = 'https://api.xero.com/files.xro/1.0/Files/'
>>> files = {'file': open('/tmp/test.txt', 'rb')}
>>> headers = {
...    'Authorization': 'Bearer secret',
...    'Xero-tenant-id': '42',
...    'Accept': 'application/json',
...    'Content-type': 'multipart/form-data; boundary=JLQPFBPUP0',
...    'Content-Length': '1068',
... }
>>> print(requests.Request('POST', post_url, files=files, headers=headers).prepare().body.decode('utf8'))
--f3e21ca5e554dd96430f07bb7a0d0e77
Content-Disposition: form-data; name="file"; filename="test.txt"


--f3e21ca5e554dd96430f07bb7a0d0e77--

As you can see the real boundary (f3e21ca5e554dd96430f07bb7a0d0e77) is different from what was passed in the header (JLQPFBPUP0).

You can actually directly use the requests module to controll boundary like this:

Let's prepare a test file:

$ touch /tmp/test.txt
$ echo 'Hello, World!' > /tmp/test.txt 

Test it:

>>> import requests
>>> post_url = 'https://api.xero.com/files.xro/1.0/Files/'
>>> files = {'file': open('/tmp/test.txt', 'rb')}
>>> headers = {
...     'Authorization': 'Bearer secret',
...     'Xero-tenant-id': '42',
...     'Accept': 'application/json',
...     'Content-Length': '1068',
... }
>>> body, content_type = requests.models.RequestEncodingMixin._encode_files(files, {})
>>> headers['Content-type'] = content_type
>>> print(requests.Request('POST', post_url, data=body, headers=headers).prepare().body.decode('utf8'))
--db57d23ff5dee7dc8dbab418e4bcb6dc
Content-Disposition: form-data; name="file"; filename="test.txt"

Hello, World!

--db57d23ff5dee7dc8dbab418e4bcb6dc--

>>> headers['Content-type']
'multipart/form-data; boundary=db57d23ff5dee7dc8dbab418e4bcb6dc'

Here boundary is the same as in the header.

Another alternative is using requests-toolbelt; below example taken from this GitHub issue thread:

from requests_toolbelt import MultipartEncoder

fields = {
    # your multipart form fields
}

m = MultipartEncoder(fields, boundary='my_super_custom_header')
r = requests.post(url, headers={'Content-Type': m.content_type}, data=m.to_string())

But it is better not to pass bundary by hand at all and entrust this work to the requests library.

---

Update:

A minimal working example using Xero Files API and Python request:

from os.path import abspath
import requests

access_token = 'secret'
tenant_id = 'secret'

filename = abspath('./example.png')

post_url = 'https://api.xero.com/files.xro/1.0/Files'
files = {'filename': open(filename, 'rb')}
values = {'name': 'Xero'}

headers = {
    'Authorization': f'Bearer {access_token}',
    'Xero-tenant-id': f'{tenant_id}',
    'Accept': 'application/json',
}

response = requests.post(
    post_url,
    headers=headers,
    files=files,
    data=values
)

assert response.status_code == 201