I am trying to do the following with requests
:
data = {'hello', 'goodbye'} json_data = json.dumps(data) headers = { 'Access-Key': self.api_key, 'Access-Signature': signature, 'Access-Nonce': nonce, 'Content-Type': 'application/json', 'Accept': 'text/plain' } r = requests.post(url, headers=headers, data=json_data, files={'file': open('/Users/david/Desktop/a.png', 'rb')})
However, I get the following error:
ValueError: Data must not be a string.
Note that if I remove the files
parameter, it works as needed. Why won’t requests
allow me to send a json-encoded string for data if files
is included?
Note that if I change data
to be just the normal python dictionary (and not a json-encoded string), the above works. So it seems that the issue is that if files is not json-encoded, then data cannot be json-encoded. However, I need to have my data encoded to match a hash signature that’s being created by the API.
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Answer
When you specify your body to a JSON string, you can no longer attach a file since file uploading requires the MIME type multipart/form-data
.
You have two options:
- Encapsulate your JSON string as part as the form data (something like
json => json.dumps(data)
) - Encode your file in Base64 and transmit it in the JSON request body. This looks like a lot of work though.