I try to use the "pygubu" module. I installed it via pip.
I can import it in my script but pygubu.Builder() throws an attribute error.
If I do import it via console and start the script afterwards. There is no error and the script runs. 
In the internet I found a wrong pythonpath could be the problem but I checked it, the pythonpath is pointing to the installation folder.
Do you know what could be wrong?
Problem solved.
The problem was my script was named "pygubu.py"(same as the module i tried to import), after renaming it, everything worked. Thanks to Bryan Oakley for that info.
Python attribut error