import dropboxlogin, requests
url = 'http://313e5987718b346aaf83-f5e825270f29a84f7881423410384342.r78.cf1.rackcdn.com/Pythonista_-_screenshotscopy.PNG'
dropbox_file_name = '/Public/test.png'
image_buffer = requests.get(url).content
#image_buffer.seek(0) # this line is not required!?!
dropbox_client = dropboxlogin.get_client()
response = dropbox_client.put_file(dropbox_file_name, image_buffer)
print(response)
... or ...
import dropboxlogin, requests
url = 'http://313e5987718b346aaf83-f5e825270f29a84f7881423410384342.r78.cf1.rackcdn.com/Pythonista_-_screenshotscopy.PNG'
dropbox_file_name = '/Public/test.png'
dropbox_client = dropboxlogin.get_client()
response = dropbox_client.put_file(dropbox_file_name, requests.get(url).content)
print(response)