When I was in version 10.5, I used python IDE quite successfully using Spyder (I did not use Jupyter Notebook). After I updated recently to 10.6, I seem to be getting this error. I checked and the Desktop10.6.pth file is in the C:\Python27\ArcGIS10.6\Lib\site-packages folder, and it contains the lines:
C:\Program Files (x86)\ArcGIS\Desktop10.6\bin
C:\Program Files (x86)\ArcGIS\Desktop10.6\ArcPy
C:\Program Files (x86)\ArcGIS\Desktop10.6\ArcToolBox\Scripts
I tried working out of Jupyter Notebook, but received the same error. It seem that these IDEs can not find the path. I have tried repairing the installation, to no effect.
I have a ArcGIS Desktop 10.6 Basic License.
I am unsure how to proceed.
Edit: I should also mentioned that I ran:
import sys
print sys.path
And it reads
'C:\\Python27\\ArcGIS10.6\\Lib\\site-packages',