Thanks so much! Now it works! I followed the instructions but missed that the version is very important. homebrew installed the newest version (3.7). Then I installed the 3.6.3 version via the "app" version from Pythons homepage (installed in Library...), which I shouldn't have done. Then I found the 3.6.5 version via homebrew which installed it in the "cellar". python3 started different versions depending on the .profile but I didn't manage to get the right one started in SAMSON. Thanks again for excellent help!

Ok, thanks, that makes sense. I will try that.

Thanks so much for your help! Yes, when I click on the icon, the window appears without an embedded QtConsole. Here is the output when I start it from the command window:
Python found in the system:
Python executable: /Library/Frameworks/Python.framework/Versions/3.6/bin/python3
3.6.3 (v3.6.3:2c5fed86e0, Oct 3 2017, 00:32:08)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)]
Traceback (most recent call last):
File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'qtconsole'

Now I managed to get all versions except the right Python version (3.6.5). The icon appears now but there is no text. Starting the console in a command window works. I use Mac.
Jupyter QtConsole 4.3.1
Python 3.6.5 (default, Jun 17 2018, 12:13:06)
Type 'copyright', 'credits' or 'license' for more information
IPython 6.2.1 -- An enhanced Interactive Python. Type '?' for help.

Hello Dmitriy, thanks for your answer. I installed everything as it said in the instructions. When I start the console, I get the following text
Jupyter QtConsole 4.4.3
Python 3.7.2 (default, Dec 27 2018, 07:35:06)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.2.0 -- An enhanced Interactive Python. Type '?' for help.
Can you see what is wrong there? Thanks again, Diana

I added the Python scripting element and it installed after restarting SAMSON. However neither the icon nor the menu appeared. I installed Jupyter Qt Console successfully. Any idea how to get the Python scripting element installation working?