This a common python path issue, to make sure it isn't your case, type :
import sys
print(sys.path)
and check if it contains:
/usr/local/lib64/python3.6/site-packages
The problem is that you install the package using pip somewhere, and you're trying to import it from somewhere else where it's not installed. The trick to solve it is by running this command :
export PYTHONPATH=$PYTHONPATH:/path/to/your/modules
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…