'dropbox is not a package'

So I'm trying to get started with backup-and-restore.py. I've run pip3 install --user dropbox, and the output of find /usr -name dropbox is 

$ find /usr -name dropbox
/usr/lib/python2.7/site-packages/dropbox
/usr/lib/python3.6/site-packages/dropbox

So it's definitely installed. However, running the file leads to 

Traceback (most recent call last):
File "dropbox.py", line 4, in <module>
import dropbox
File "/home/amr/Downloads/dropbox.py", line 5, in <module>
from dropbox.files import WriteMode
ModuleNotFoundError: No module named 'dropbox.files'; 'dropbox' is not a package

I also went into a python console and did

import sys

print(sys.path)

['', '/usr/lib64/python36.zip', '/usr/lib64/python3.6', '/usr/lib64/python3.6/lib-dynload', '/home/amr/.local/lib/python3.6/site-packages', '/usr/lib64/python3.6/site-packages', '/usr/lib/python3.6/site-packages']

So it should definitely be finding it. Has anyone else had this error or can offer any advice? I was hoping to get this up and running quickly and not be falling at the first hurdle.